Convert CaptureConfigTest and SessionConfigTest to host tests

  Currently, they are device tests but don't have any device dependencies (uses fake/mock dependencies for surfaces). Converting them to host tests will ensure they are always run at AOSP presubmit if relevant code is changed.

Bug: N/A
Test: ./gradlew bOS
Change-Id: Ibdd138830dcc70b4fbc2f5b0d22b8ec47f8e3a05

4 files changed, 1618 insertions, 1460 deletions

diff --git a/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/CaptureConfigTest.java b/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/CaptureConfigTest.java
deleted file mode 100644
index be2063057ed..00000000000
--- a/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/CaptureConfigTest.java
+++ /dev/null
@@ -1,359 +0,0 @@
-/*
- * Copyright 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package androidx.camera.core.impl;
-
-import static androidx.camera.core.impl.Config.OptionPriority.REQUIRED;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import static org.mockito.Mockito.mock;
-
-import android.hardware.camera2.CameraDevice;
-import android.util.Range;
-import android.view.Surface;
-
-import androidx.annotation.NonNull;
-import androidx.camera.core.impl.Config.Option;
-import androidx.camera.testing.impl.DeferrableSurfacesUtil;
-import androidx.test.ext.junit.runners.AndroidJUnit4;
-import androidx.test.filters.LargeTest;
-import androidx.test.filters.SdkSuppress;
-
-import com.google.common.collect.Lists;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import java.util.Arrays;
-import java.util.List;
-
-@LargeTest
-@RunWith(AndroidJUnit4.class)
-@SdkSuppress(minSdkVersion = 21)
-public class CaptureConfigTest {
-    private static final Option<Integer> OPTION = Config.Option.create(
-            "camerax.test.option_0", Integer.class);
-
-    private DeferrableSurface mMockSurface0;
-    private static final Config.Option<FakeMultiValueSet> FAKE_MULTI_VALUE_SET_OPTION =
-            Config.Option.create("option.fakeMultiValueSet.1", FakeMultiValueSet.class);
-
-    @Before
-    public void setup() {
-        mMockSurface0 = mock(DeferrableSurface.class);
-    }
-
-    @Test
-    public void builderSetTemplate() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        CaptureConfig captureConfig = builder.build();
-
-        assertThat(captureConfig.getTemplateType()).isEqualTo(CameraDevice.TEMPLATE_PREVIEW);
-    }
-
-    @Test
-    public void builderNotSetTemplate() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        CaptureConfig captureConfig = builder.build();
-
-        assertThat(captureConfig.getTemplateType()).isEqualTo(CaptureConfig.TEMPLATE_TYPE_NONE);
-    }
-
-    @Test
-    public void builderAddSurface() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        CaptureConfig captureConfig = builder.build();
-
-        List<DeferrableSurface> surfaces = captureConfig.getSurfaces();
-
-        assertThat(surfaces).hasSize(1);
-        assertThat(surfaces).contains(mMockSurface0);
-    }
-
-    @Test
-    public void builderRemoveSurface() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        builder.removeSurface(mMockSurface0);
-        CaptureConfig captureConfig = builder.build();
-
-        List<Surface> surfaces = DeferrableSurfacesUtil.surfaceList(captureConfig.getSurfaces());
-        assertThat(surfaces).isEmpty();
-    }
-
-    @Test
-    public void builderClearSurface() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        builder.clearSurfaces();
-        CaptureConfig captureConfig = builder.build();
-
-        List<Surface> surfaces = DeferrableSurfacesUtil.surfaceList(captureConfig.getSurfaces());
-        assertThat(surfaces.size()).isEqualTo(0);
-    }
-
-    @Test
-    public void builderAddOption() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        MutableOptionsBundle options = MutableOptionsBundle.create();
-        options.insertOption(OPTION, 1);
-        builder.addImplementationOptions(options);
-        CaptureConfig captureConfig = builder.build();
-
-        Config config = captureConfig.getImplementationOptions();
-
-        assertThat(config.containsOption(OPTION)).isTrue();
-        assertThat(config.retrieveOption(OPTION)).isEqualTo(1);
-    }
-
-    @Test
-    public void addOption_priorityIsKept() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        MutableOptionsBundle options = MutableOptionsBundle.create();
-        options.insertOption(OPTION, REQUIRED, 1);
-        builder.addImplementationOptions(options);
-        CaptureConfig captureConfig = builder.build();
-
-        Config config = captureConfig.getImplementationOptions();
-
-        assertThat(config.containsOption(OPTION)).isTrue();
-        assertThat(config.retrieveOption(OPTION)).isEqualTo(1);
-        assertThat(config.getOptionPriority(OPTION)).isEqualTo(REQUIRED);
-    }
-
-    @Test
-    public void builderSetUseTargetedSurface() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.setUseRepeatingSurface(true);
-        CaptureConfig captureConfig = builder.build();
-
-        assertThat(captureConfig.isUseRepeatingSurface()).isTrue();
-    }
-
-    @Test
-    public void builderAddMultipleCameraCaptureCallbacks() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-
-        builder.addCameraCaptureCallback(callback0);
-        builder.addCameraCaptureCallback(callback1);
-        CaptureConfig configuration = builder.build();
-
-        assertThat(configuration.getCameraCaptureCallbacks()).containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddAllCameraCaptureCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        List<CameraCaptureCallback> callbacks = Lists.newArrayList(callback0, callback1);
-
-        builder.addAllRepeatingCameraCaptureCallbacks(callbacks);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddImplementationMultiValue() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        Object obj1 = new Object();
-        FakeMultiValueSet fakeMultiValueSet1 = new FakeMultiValueSet();
-        fakeMultiValueSet1.addAll(Arrays.asList(obj1));
-        MutableOptionsBundle fakeConfig1 = MutableOptionsBundle.create();
-        fakeConfig1.insertOption(FAKE_MULTI_VALUE_SET_OPTION, fakeMultiValueSet1);
-        builder.addImplementationOptions(fakeConfig1);
-
-        Object obj2 = new Object();
-        FakeMultiValueSet fakeMultiValueSet2 = new FakeMultiValueSet();
-        fakeMultiValueSet2.addAll(Arrays.asList(obj2));
-        MutableOptionsBundle fakeConfig2 = MutableOptionsBundle.create();
-        fakeConfig2.insertOption(FAKE_MULTI_VALUE_SET_OPTION, fakeMultiValueSet2);
-        builder.addImplementationOptions(fakeConfig2);
-
-        CaptureConfig captureConfig = builder.build();
-
-        FakeMultiValueSet fakeMultiValueSet =
-                captureConfig.getImplementationOptions().retrieveOption(
-                        FAKE_MULTI_VALUE_SET_OPTION);
-
-        assertThat(fakeMultiValueSet).isNotNull();
-        assertThat(fakeMultiValueSet.getAllItems()).containsExactly(obj1, obj2);
-    }
-
-    @Test
-    public void builderAddSingleImplementationOption() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        builder.addImplementationOption(CaptureConfig.OPTION_ROTATION, 90);
-
-        CaptureConfig captureConfig = builder.build();
-
-        assertThat(captureConfig.getImplementationOptions().retrieveOption(
-                CaptureConfig.OPTION_ROTATION)).isEqualTo(90);
-    }
-
-    @Test
-    public void builderFromPrevious_containsCameraCaptureCallbacks() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        builder.addCameraCaptureCallback(callback0);
-        builder.addCameraCaptureCallback(callback1);
-        builder = CaptureConfig.Builder.from(builder.build());
-        CameraCaptureCallback callback2 = mock(CameraCaptureCallback.class);
-
-        builder.addCameraCaptureCallback(callback2);
-        CaptureConfig configuration = builder.build();
-
-        assertThat(configuration.getCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1, callback2);
-    }
-
-    @Test
-    public void builderRemoveCameraCaptureCallback_returnsFalseIfNotAdded() {
-        CameraCaptureCallback mockCallback = mock(CameraCaptureCallback.class);
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        assertThat(builder.removeCameraCaptureCallback(mockCallback)).isFalse();
-    }
-
-    @Test
-    public void builderRemoveCameraCaptureCallback_removesAddedCallback() {
-        // Arrange.
-        CameraCaptureCallback mockCallback = mock(CameraCaptureCallback.class);
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        // Act.
-        builder.addCameraCaptureCallback(mockCallback);
-        CaptureConfig configWithCallback = builder.build();
-
-        // Assert.
-        assertThat(configWithCallback.getCameraCaptureCallbacks()).contains(mockCallback);
-
-        // Act.
-        boolean removedCallback = builder.removeCameraCaptureCallback(mockCallback);
-        CaptureConfig configWithoutCallback = builder.build();
-
-        // Assert.
-        assertThat(removedCallback).isTrue();
-        assertThat(configWithoutCallback.getCameraCaptureCallbacks()).doesNotContain(mockCallback);
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void cameraCaptureCallbacks_areImmutable() {
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-        CaptureConfig configuration = builder.build();
-
-        configuration.getCameraCaptureCallbacks().add(mock(CameraCaptureCallback.class));
-    }
-
-    @Test
-    public void postviewEnabledDefaultIsFalse() {
-        // 1. Arrange / Act
-        CaptureConfig captureConfig = new CaptureConfig.Builder().build();
-
-        // 3. Assert
-        assertThat(captureConfig.isPostviewEnabled()).isFalse();
-    }
-
-    @Test
-    public void canSetPostviewEnabled() {
-        // 1. Arrange
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-
-        // 2. Act
-        builder.setPostviewEnabled(true);
-        CaptureConfig captureConfig = builder.build();
-
-        // 3. Assert
-        assertThat(captureConfig.isPostviewEnabled()).isTrue();
-
-    }
-
-    @Test
-    public void builderChange_doNotChangeEarlierBuiltInstance() {
-        // 1. Arrange
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback2 = mock(CameraCaptureCallback.class);
-        DeferrableSurface deferrableSurface1 = mock(DeferrableSurface.class);
-        DeferrableSurface deferrableSurface2 = mock(DeferrableSurface.class);
-        Range<Integer> fpsRange1 = new Range<>(30, 30);
-        Range<Integer> fpsRange2 = new Range<>(15, 30);
-        int optionValue1 = 1;
-        int optionValue2 = 2;
-        int tagValue1 = 1;
-        int tagValue2 = 2;
-        int template1 = CameraDevice.TEMPLATE_PREVIEW;
-        int template2 = CameraDevice.TEMPLATE_RECORD;
-
-        CaptureConfig.Builder builder = new CaptureConfig.Builder();
-        builder.addSurface(deferrableSurface1);
-        builder.setExpectedFrameRateRange(fpsRange1);
-        builder.addCameraCaptureCallback(callback1);
-        builder.setTemplateType(template1);
-        builder.addTag("KEY", tagValue1);
-        builder.addImplementationOption(OPTION, optionValue1);
-        CaptureConfig captureConfig = builder.build();
-
-        // 2. Act
-        // builder change should not affect the instance built earlier.
-        builder.addSurface(deferrableSurface2);
-        builder.setExpectedFrameRateRange(fpsRange2);
-        builder.addCameraCaptureCallback(callback2);
-        builder.setTemplateType(template2);
-        builder.addTag("KEY", tagValue2);
-        builder.addImplementationOption(OPTION, optionValue2);
-
-        // 3. Verify
-        assertThat(captureConfig.getSurfaces()).containsExactly(deferrableSurface1);
-        assertThat(captureConfig.getExpectedFrameRateRange()).isEqualTo(fpsRange1);
-        assertThat(captureConfig.getCameraCaptureCallbacks()).containsExactly(callback1);
-        assertThat(captureConfig.getTemplateType()).isEqualTo(template1);
-        assertThat(captureConfig.getTagBundle().getTag("KEY")).isEqualTo(tagValue1);
-        assertThat(captureConfig.getImplementationOptions().retrieveOption(OPTION))
-                .isEqualTo(optionValue1);
-    }
-
-    /**
-     * A fake {@link MultiValueSet}.
-     */
-    static class FakeMultiValueSet extends MultiValueSet<Object> {
-        @NonNull
-        @Override
-        public MultiValueSet<Object> clone() {
-            FakeMultiValueSet multiValueSet = new FakeMultiValueSet();
-            multiValueSet.addAll(getAllItems());
-            return multiValueSet;
-        }
-    }
-}
diff --git a/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/SessionConfigTest.java b/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/SessionConfigTest.java
deleted file mode 100644
index 5ae7d2d90a3..00000000000
--- a/camera/camera-core/src/androidTest/java/androidx/camera/core/impl/SessionConfigTest.java
+++ /dev/null
@@ -1,1101 +0,0 @@
-/*
- * Copyright 2019 The Android Open Source Project
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *      http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-package androidx.camera.core.impl;
-
-import static androidx.camera.core.impl.SessionConfig.OutputConfig.SURFACE_GROUP_ID_NONE;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import static org.mockito.Mockito.mock;
-
-import android.hardware.camera2.CameraCaptureSession;
-import android.hardware.camera2.CameraDevice;
-import android.hardware.camera2.params.SessionConfiguration;
-import android.util.Range;
-import android.view.Surface;
-
-import androidx.camera.camera2.impl.Camera2ImplConfig;
-import androidx.camera.core.ImageCapture;
-import androidx.camera.core.Preview;
-import androidx.camera.core.impl.Config.Option;
-import androidx.camera.testing.impl.DeferrableSurfacesUtil;
-import androidx.camera.testing.impl.fakes.FakeMultiValueSet;
-import androidx.test.ext.junit.runners.AndroidJUnit4;
-import androidx.test.filters.MediumTest;
-import androidx.test.filters.SdkSuppress;
-
-import com.google.common.collect.Lists;
-
-import org.junit.After;
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-
-import java.util.Arrays;
-import java.util.List;
-
-@MediumTest
-@RunWith(AndroidJUnit4.class)
-@SdkSuppress(minSdkVersion = 21)
-public class SessionConfigTest {
-    private static final Option<Integer> OPTION = Option.create(
-            "camerax.test.option_0", Integer.class);
-    private static final Option<String> OPTION_1 = Option.create(
-            "camerax.test.option_1", String.class);
-    private DeferrableSurface mMockSurface0;
-    private DeferrableSurface mMockSurface1;
-
-    @Before
-    public void setup() {
-        mMockSurface0 = new ImmediateSurface(mock(Surface.class));
-        mMockSurface1 = new ImmediateSurface(mock(Surface.class));
-    }
-
-    @After
-    public void tearDown() {
-        mMockSurface0.close();
-        mMockSurface1.close();
-    }
-
-    @Test
-    public void builderSetTemplate() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfig = builder.build();
-
-        assertThat(sessionConfig.getTemplateType()).isEqualTo(CameraDevice.TEMPLATE_PREVIEW);
-    }
-
-    @Test
-    public void builderAddSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        SessionConfig sessionConfig = builder.build();
-
-        List<DeferrableSurface> surfaces = sessionConfig.getSurfaces();
-        List<SessionConfig.OutputConfig> outputConfigs = sessionConfig.getOutputConfigs();
-
-        assertThat(surfaces).hasSize(1);
-        assertThat(surfaces).contains(mMockSurface0);
-        assertThat(outputConfigs).hasSize(1);
-        assertThat(outputConfigs.get(0).getSurface()).isEqualTo(mMockSurface0);
-        assertThat(outputConfigs.get(0).getSharedSurfaces()).isEmpty();
-        assertThat(outputConfigs.get(0).getPhysicalCameraId()).isNull();
-        assertThat(outputConfigs.get(0).getSurfaceGroupId()).isEqualTo(SURFACE_GROUP_ID_NONE);
-    }
-
-    @Test
-    public void builderAddOutputConfig() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        DeferrableSurface sharedSurface1 = new ImmediateSurface(mock(Surface.class));
-        DeferrableSurface sharedSurface2 = new ImmediateSurface(mock(Surface.class));
-        SessionConfig.OutputConfig outputConfig = SessionConfig.OutputConfig.builder(mMockSurface0)
-                .setSurfaceGroupId(1)
-                .setSharedSurfaces(Arrays.asList(sharedSurface1, sharedSurface2))
-                .setPhysicalCameraId("4")
-                .build();
-
-        builder.addOutputConfig(outputConfig);
-        SessionConfig sessionConfig = builder.build();
-
-        List<DeferrableSurface> surfaces = sessionConfig.getSurfaces();
-        List<SessionConfig.OutputConfig> outputConfigs = sessionConfig.getOutputConfigs();
-
-        assertThat(surfaces).containsExactly(mMockSurface0, sharedSurface1, sharedSurface2);
-        assertThat(outputConfigs).hasSize(1);
-        assertThat(outputConfigs.get(0).getSurface()).isEqualTo(mMockSurface0);
-        assertThat(outputConfigs.get(0).getSharedSurfaces())
-                .containsExactly(sharedSurface1, sharedSurface2);
-        assertThat(outputConfigs.get(0).getSurfaceGroupId()).isEqualTo(1);
-        assertThat(outputConfigs.get(0).getPhysicalCameraId()).isEqualTo("4");
-    }
-
-    @Test
-    public void builderAddNonRepeatingSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.addNonRepeatingSurface(mMockSurface0);
-        SessionConfig sessionConfig = builder.build();
-
-        List<DeferrableSurface> surfaces = sessionConfig.getSurfaces();
-        List<SessionConfig.OutputConfig> outputConfigs = sessionConfig.getOutputConfigs();
-        List<DeferrableSurface> repeatingSurfaces =
-                sessionConfig.getRepeatingCaptureConfig().getSurfaces();
-
-        assertThat(surfaces).containsExactly(mMockSurface0);
-        assertThat(outputConfigs).hasSize(1);
-        assertThat(outputConfigs.get(0).getSurface()).isEqualTo(mMockSurface0);
-        assertThat(repeatingSurfaces).isEmpty();
-        assertThat(repeatingSurfaces).doesNotContain(mMockSurface0);
-    }
-
-    @Test
-    public void builderAddSurfaceContainsRepeatingSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        builder.addNonRepeatingSurface(mMockSurface1);
-        SessionConfig sessionConfig = builder.build();
-
-        List<Surface> surfaces = DeferrableSurfacesUtil.surfaceList(sessionConfig.getSurfaces());
-        List<Surface> repeatingSurfaces = DeferrableSurfacesUtil.surfaceList(
-                sessionConfig.getRepeatingCaptureConfig().getSurfaces());
-
-        assertThat(surfaces.size()).isAtLeast(repeatingSurfaces.size());
-        assertThat(surfaces).containsAtLeastElementsIn(repeatingSurfaces);
-    }
-
-    @Test
-    public void builderRemoveSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        builder.addSurface(mMockSurface1);
-        builder.removeSurface(mMockSurface0);
-        SessionConfig sessionConfig = builder.build();
-
-        assertThat(sessionConfig.getSurfaces()).containsExactly(mMockSurface1);
-        assertThat(sessionConfig.getOutputConfigs()).hasSize(1);
-        assertThat(sessionConfig.getOutputConfigs().get(0).getSurface()).isEqualTo(mMockSurface1);
-    }
-
-    @Test
-    public void builderClearSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        builder.addSurface(mMockSurface0);
-        builder.clearSurfaces();
-        SessionConfig sessionConfig = builder.build();
-
-        assertThat(sessionConfig.getSurfaces()).isEmpty();
-        assertThat(sessionConfig.getOutputConfigs()).isEmpty();
-    }
-
-    @Test
-    public void builderAddOption() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        MutableOptionsBundle options = MutableOptionsBundle.create();
-        options.insertOption(OPTION, 1);
-        builder.addImplementationOptions(options);
-        SessionConfig sessionConfig = builder.build();
-
-        Config config = sessionConfig.getImplementationOptions();
-
-        assertThat(config.containsOption(OPTION)).isTrue();
-        assertThat(config.retrieveOption(OPTION)).isEqualTo(1);
-    }
-
-    @Test
-    public void builderDefaultSessionTypeIsRegular() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig sessionConfig = builder.build();
-        assertThat(sessionConfig.getSessionType() == SessionConfiguration.SESSION_REGULAR);
-    }
-
-    @Test
-    public void builderSetSessionType() {
-        SessionConfig.Builder builder = new SessionConfig.Builder()
-                .setSessionType(2);
-        SessionConfig sessionConfig = builder.build();
-        assertThat(sessionConfig.getSessionType() == 2);
-    }
-
-    @Test
-    public void builderSetPostviewSurface() {
-        SessionConfig.Builder builder = new SessionConfig.Builder()
-                .setPostviewSurface(mMockSurface0);
-        SessionConfig sessionConfig = builder.build();
-        assertThat(sessionConfig.getPostviewOutputConfig().getSurface()).isEqualTo(mMockSurface0);
-    }
-
-    @Test
-    public void prioritizeTemplateType_previewHigherThanUnsupportedType() {
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-        SessionConfig.Builder builderManual = new SessionConfig.Builder();
-        builderManual.setTemplateType(CameraDevice.TEMPLATE_MANUAL);
-        SessionConfig sessionConfigManual = builderManual.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-        validatingBuilder.add(sessionConfigManual);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getTemplateType()).isEqualTo(
-                CameraDevice.TEMPLATE_PREVIEW);
-    }
-
-    @Test
-    public void prioritizeTemplateType_recordHigherThanPreview() {
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-        SessionConfig.Builder builderRecord = new SessionConfig.Builder();
-        builderRecord.setTemplateType(CameraDevice.TEMPLATE_RECORD);
-        SessionConfig sessionConfigRecord = builderRecord.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-        validatingBuilder.add(sessionConfigRecord);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getTemplateType()).isEqualTo(
-                CameraDevice.TEMPLATE_RECORD);
-    }
-
-    @Test
-    public void prioritizeTemplateType_addZslFirst_zslHigherThanPreview() {
-        SessionConfig.Builder builderZsl = new SessionConfig.Builder();
-        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-        SessionConfig sessionConfigZsl = builderZsl.build();
-
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigZsl);
-        validatingBuilder.add(sessionConfigPreview);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getTemplateType()).isEqualTo(
-                CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-    }
-
-    @Test
-    public void prioritizeTemplateType_addPreviewFirst_zslHigherThanPreview() {
-        SessionConfig.Builder builderZsl = new SessionConfig.Builder();
-        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-        SessionConfig sessionConfigZsl = builderZsl.build();
-
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-        validatingBuilder.add(sessionConfigZsl);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getTemplateType()).isEqualTo(
-                CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-    }
-
-    @Test
-    public void setAndVerifyExpectedFrameRateRange_nullValue() {
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getExpectedFrameRateRange()).isEqualTo(
-                StreamSpec.FRAME_RATE_RANGE_UNSPECIFIED);
-    }
-
-    @Test
-    public void setAndVerifyExpectedFrameRateRange_initialValue() {
-        Range<Integer> fpsRangeLow = new Range<>(30, 45);
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        builderPreview.setExpectedFrameRateRange(fpsRangeLow);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getExpectedFrameRateRange()).isEqualTo(
-                fpsRangeLow);
-    }
-
-    @Test
-    public void setAndVerifyExpectedFrameRateRange_sameValues() {
-        Range<Integer> fpsRangeLow = new Range<>(30, 45);
-        SessionConfig.Builder builderZsl = new SessionConfig.Builder();
-        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-        builderZsl.setExpectedFrameRateRange(fpsRangeLow);
-        SessionConfig sessionConfigZsl = builderZsl.build();
-
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        builderPreview.setExpectedFrameRateRange(fpsRangeLow);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-        validatingBuilder.add(sessionConfigZsl);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        assertThat(validatingBuilder.build().getExpectedFrameRateRange()).isEqualTo(
-                fpsRangeLow);
-    }
-
-    @Test
-    public void setAndVerifyExpectedFrameRateRange_differentValues() {
-        Range<Integer> fpsRangeLow = new Range<>(30, 45);
-        Range<Integer> fpsRangeHigh = new Range<>(45, 60);
-        SessionConfig.Builder builderZsl = new SessionConfig.Builder();
-        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG);
-        builderZsl.setExpectedFrameRateRange(fpsRangeLow);
-        SessionConfig sessionConfigZsl = builderZsl.build();
-
-        SessionConfig.Builder builderPreview = new SessionConfig.Builder();
-        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        builderPreview.setExpectedFrameRateRange(fpsRangeHigh);
-        SessionConfig sessionConfigPreview = builderPreview.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(sessionConfigPreview);
-        validatingBuilder.add(sessionConfigZsl);
-
-        assertThat(validatingBuilder.isValid()).isFalse();
-    }
-
-    @Test
-    public void addImplementationOptionForStreamUseCase() {
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        assertThat(!validatingBuilder.build().getImplementationOptions().containsOption(
-                Camera2ImplConfig.STREAM_USE_CASE_OPTION));
-        validatingBuilder.addImplementationOption(Camera2ImplConfig.STREAM_USE_CASE_OPTION, 1L);
-        assertThat(validatingBuilder.build().getImplementationOptions().retrieveOption(
-                Camera2ImplConfig.STREAM_USE_CASE_OPTION) == 1L);
-    }
-
-    @Test
-    public void addDifferentNonDefaultSessionType() {
-        // 1. Arrange.
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        SessionConfig sessionConfig1 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setSessionType(1).build();
-        SessionConfig sessionConfig2 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setSessionType(2).build();
-
-        // 2. Act.
-        validatingBuilder.add(sessionConfig1);
-        validatingBuilder.add(sessionConfig2);
-
-        // 3. Assert.
-        assertThat(validatingBuilder.isValid()).isFalse();
-    }
-
-    @Test
-    public void addDefaultAndThenNonDefaultSessionType() {
-        // 1. Arrange.
-        final int sessionTypeToVerify = 2;
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        SessionConfig sessionConfig1 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW).build();
-        SessionConfig sessionConfig2 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setSessionType(sessionTypeToVerify).build();
-
-        // 2. Act.
-        validatingBuilder.add(sessionConfig1);
-        validatingBuilder.add(sessionConfig2);
-
-        // 3. Assert.
-        assertThat(validatingBuilder.build().getSessionType()).isEqualTo(sessionTypeToVerify);
-        assertThat(validatingBuilder.isValid()).isTrue();
-    }
-
-    @Test
-    public void addNonDefaultAndThenDefaultSessionType() {
-        // 1. Arrange.
-        final int sessionTypeToVerify = 2;
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        SessionConfig sessionConfig1 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setSessionType(sessionTypeToVerify).build();
-        SessionConfig sessionConfig2 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW).build();
-
-        // 2. Act.
-        validatingBuilder.add(sessionConfig1);
-        validatingBuilder.add(sessionConfig2);
-
-        // 3. Assert.
-        assertThat(validatingBuilder.build().getSessionType()).isEqualTo(sessionTypeToVerify);
-        assertThat(validatingBuilder.isValid()).isTrue();
-    }
-
-    @Test
-    public void addPostviewSurfaceTo_validatingBuilder() {
-        // 1. Arrange.
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        SessionConfig sessionConfig1 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setPostviewSurface(mMockSurface0)
-                .build();
-
-        // 2. Act.
-        validatingBuilder.add(sessionConfig1);
-
-        // 3. Assert.
-        assertThat(validatingBuilder.build().getPostviewOutputConfig().getSurface())
-                .isEqualTo(mMockSurface0);
-        assertThat(validatingBuilder.isValid()).isTrue();
-    }
-
-    @Test
-    public void addDifferentPostviewSurfacesTo_validatingBuilder() {
-        // 1. Arrange.
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        SessionConfig sessionConfig1 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setPostviewSurface(mMockSurface0)
-                .build();
-        SessionConfig sessionConfig2 = new SessionConfig.Builder()
-                .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
-                .setPostviewSurface(mMockSurface1)
-                .build();
-
-        // 2. Act.
-        validatingBuilder.add(sessionConfig1);
-        validatingBuilder.add(sessionConfig2);
-
-        // 3. Assert.
-        assertThat(validatingBuilder.isValid()).isFalse();
-    }
-
-    @Test
-    public void conflictingOptions() {
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        MutableOptionsBundle options0 = MutableOptionsBundle.create();
-        options0.insertOption(OPTION, 1);
-        builder0.addImplementationOptions(options0);
-        SessionConfig config0 = builder0.build();
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        MutableOptionsBundle options1 = MutableOptionsBundle.create();
-        options1.insertOption(OPTION, 2);
-        builder1.addImplementationOptions(options1);
-        SessionConfig config1 = builder1.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-
-        validatingBuilder.add(config0);
-        validatingBuilder.add(config1);
-
-        assertThat(validatingBuilder.isValid()).isFalse();
-    }
-
-    @Test
-    public void combineTwoSessionsValid() {
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        builder0.addSurface(mMockSurface0);
-        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options0 = MutableOptionsBundle.create();
-        options0.insertOption(OPTION, 1);
-        builder0.addImplementationOptions(options0);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        builder1.addSurface(mMockSurface1);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options1 = MutableOptionsBundle.create();
-        options1.insertOption(OPTION_1, "test");
-        builder1.addImplementationOptions(options1);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder0.build());
-        validatingBuilder.add(builder1.build());
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-    }
-
-    @Test
-    public void combineTwoSessionsTemplate() {
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        builder0.addSurface(mMockSurface0);
-        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options0 = MutableOptionsBundle.create();
-        options0.insertOption(OPTION, 1);
-        builder0.addImplementationOptions(options0);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        builder1.addSurface(mMockSurface1);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options1 = MutableOptionsBundle.create();
-        options1.insertOption(OPTION_1, "test");
-        builder1.addImplementationOptions(options1);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder0.build());
-        validatingBuilder.add(builder1.build());
-
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        assertThat(sessionConfig.getTemplateType()).isEqualTo(CameraDevice.TEMPLATE_PREVIEW);
-    }
-
-    private DeferrableSurface createSurface(Class<?> containerClass) {
-        DeferrableSurface deferrableSurface = new ImmediateSurface(mock(Surface.class));
-        deferrableSurface.setContainerClass(containerClass);
-        return deferrableSurface;
-    }
-
-    @Test
-    public void combineTwoSessionsSurfaces() {
-        DeferrableSurface previewSurface = createSurface(Preview.class);
-        DeferrableSurface imageCaptureSurface = createSurface(ImageCapture.class);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        builder1.addSurface(previewSurface);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-
-        SessionConfig.Builder builder2 = new SessionConfig.Builder();
-        builder2.addSurface(imageCaptureSurface);
-        builder2.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder1.build());
-        validatingBuilder.add(builder2.build());
-
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        List<DeferrableSurface> surfaces = sessionConfig.getSurfaces();
-        // Ensures the surfaces are all added and sorted correctly.
-        assertThat(surfaces).containsExactly(previewSurface, imageCaptureSurface).inOrder();
-    }
-
-    @Test
-    public void combineTwoSessionsOutputConfigs() {
-        DeferrableSurface nonRepeatingSurface = mock(DeferrableSurface.class);
-
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        SessionConfig.OutputConfig outputConfig0 =
-                SessionConfig.OutputConfig.builder(mMockSurface0).build();
-        builder0.addOutputConfig(outputConfig0);
-        builder0.addNonRepeatingSurface(nonRepeatingSurface);
-        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        SessionConfig.OutputConfig outputConfig1 =
-                SessionConfig.OutputConfig.builder(mMockSurface1).build();
-        builder1.addOutputConfig(outputConfig1);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder0.build());
-        validatingBuilder.add(builder1.build());
-
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        List<DeferrableSurface> surfaces = sessionConfig.getSurfaces();
-        assertThat(surfaces).containsExactly(mMockSurface0, mMockSurface1, nonRepeatingSurface);
-        assertThat(sessionConfig.getOutputConfigs()).hasSize(3);
-        assertThat(sessionConfig.getOutputConfigs().get(0)).isEqualTo(outputConfig0);
-        assertThat(sessionConfig.getOutputConfigs().get(1).getSurface())
-                .isEqualTo(nonRepeatingSurface);
-        assertThat(sessionConfig.getOutputConfigs().get(2)).isEqualTo(outputConfig1);
-        // Should not contain the nonRepeatingSurface.
-        assertThat(sessionConfig.getRepeatingCaptureConfig().getSurfaces())
-                .containsExactly(mMockSurface0, mMockSurface1);
-    }
-
-    @Test
-    public void combineTwoSessionsOptions() {
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        builder0.addSurface(mMockSurface0);
-        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options0 = MutableOptionsBundle.create();
-        options0.insertOption(OPTION, 1);
-        builder0.addImplementationOptions(options0);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        builder1.addSurface(mMockSurface1);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options1 = MutableOptionsBundle.create();
-        options1.insertOption(OPTION_1, "test");
-        builder1.addImplementationOptions(options1);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder0.build());
-        validatingBuilder.add(builder1.build());
-
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        Config config = sessionConfig.getImplementationOptions();
-
-        assertThat(config.retrieveOption(OPTION)).isEqualTo(1);
-        assertThat(config.retrieveOption(OPTION_1)).isEqualTo("test");
-    }
-
-    @Test
-    public void combineTwoSessionsMultiValueSetValid() {
-        Option<FakeMultiValueSet> option = Option.create("multiValueSet", FakeMultiValueSet.class);
-
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        MutableOptionsBundle options0 = MutableOptionsBundle.create();
-        FakeMultiValueSet multiValueSet0 = new FakeMultiValueSet();
-        options0.insertOption(option, multiValueSet0);
-        builder0.addImplementationOptions(options0);
-        SessionConfig config0 = builder0.build();
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        MutableOptionsBundle options1 = MutableOptionsBundle.create();
-        FakeMultiValueSet multiValueSet1 = new FakeMultiValueSet();
-        options1.insertOption(option, multiValueSet1);
-        builder1.addImplementationOptions(options1);
-        SessionConfig config1 = builder1.build();
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(config0);
-        validatingBuilder.add(config1);
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-    }
-
-    @Test
-    public void builderAddMultipleRepeatingCameraCaptureCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-
-        builder.addRepeatingCameraCaptureCallback(callback0);
-        builder.addRepeatingCameraCaptureCallback(callback1);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-        assertThat(configuration.getSingleCameraCaptureCallbacks())
-                .containsNoneOf(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddAllRepeatingCameraCaptureCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        List<CameraCaptureCallback> callbacks = Lists.newArrayList(callback0, callback1);
-
-        builder.addAllRepeatingCameraCaptureCallbacks(callbacks);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-        assertThat(configuration.getSingleCameraCaptureCallbacks())
-                .containsNoneOf(callback0, callback1);
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void repeatingCameraCaptureCallbacks_areImmutable() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig configuration = builder.build();
-
-        configuration.getRepeatingCameraCaptureCallbacks().add(mock(CameraCaptureCallback.class));
-    }
-
-    @Test
-    public void builderAddMultipleDeviceStateCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraDevice.StateCallback callback0 = mock(CameraDevice.StateCallback.class);
-        CameraDevice.StateCallback callback1 = mock(CameraDevice.StateCallback.class);
-
-        builder.addDeviceStateCallback(callback0);
-        builder.addDeviceStateCallback(callback1);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getDeviceStateCallbacks()).containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddAllDeviceStateCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraDevice.StateCallback callback0 = mock(CameraDevice.StateCallback.class);
-        CameraDevice.StateCallback callback1 = mock(CameraDevice.StateCallback.class);
-        List<CameraDevice.StateCallback> callbacks = Lists.newArrayList(callback0, callback1);
-
-        builder.addAllDeviceStateCallbacks(callbacks);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getDeviceStateCallbacks()).containsExactly(callback0, callback1);
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void deviceStateCallbacks_areImmutable() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig configuration = builder.build();
-
-        configuration.getDeviceStateCallbacks().add(mock(CameraDevice.StateCallback.class));
-    }
-
-    @Test
-    public void builderAddMultipleSessionStateCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureSession.StateCallback callback0 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraCaptureSession.StateCallback callback1 =
-                mock(CameraCaptureSession.StateCallback.class);
-
-        builder.addSessionStateCallback(callback0);
-        builder.addSessionStateCallback(callback1);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getSessionStateCallbacks()).containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddAllSessionStateCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureSession.StateCallback callback0 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraCaptureSession.StateCallback callback1 =
-                mock(CameraCaptureSession.StateCallback.class);
-        List<CameraCaptureSession.StateCallback> callbacks =
-                Lists.newArrayList(callback0, callback1);
-
-        builder.addAllSessionStateCallbacks(callbacks);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getSessionStateCallbacks()).containsExactly(callback0, callback1);
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void sessionStateCallbacks_areImmutable() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig configuration = builder.build();
-
-        configuration.getSessionStateCallbacks()
-                .add(mock(CameraCaptureSession.StateCallback.class));
-    }
-
-    @Test
-    public void builderAddMultipleCameraCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-
-        builder.addCameraCaptureCallback(callback0);
-        builder.addCameraCaptureCallback(callback1);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getSingleCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-        assertThat(configuration.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void builderAddAllCameraCallbacks() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        CameraCaptureCallback callback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        List<CameraCaptureCallback> callbacks = Lists.newArrayList(callback0, callback1);
-
-        builder.addAllCameraCaptureCallbacks(callbacks);
-        SessionConfig configuration = builder.build();
-
-        assertThat(configuration.getSingleCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-        assertThat(configuration.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(callback0, callback1);
-    }
-
-    @Test
-    public void removeCameraCaptureCallback_returnsFalseIfNotAdded() {
-        CameraCaptureCallback mockCallback = mock(CameraCaptureCallback.class);
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        assertThat(builder.removeCameraCaptureCallback(mockCallback)).isFalse();
-    }
-
-    @Test
-    public void canAddAndRemoveCameraCaptureCallback_withBuilder() {
-        // Arrange.
-        CameraCaptureCallback mockRepeatingCallback = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback mockSingleCallback = mock(CameraCaptureCallback.class);
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-
-        // Act.
-        builder.addRepeatingCameraCaptureCallback(mockRepeatingCallback);
-        builder.addCameraCaptureCallback(mockSingleCallback);
-        SessionConfig sessionConfigWithCallbacks = builder.build();
-
-        // Assert.
-        assertThat(sessionConfigWithCallbacks.getSingleCameraCaptureCallbacks()).contains(
-                mockSingleCallback);
-        assertThat(sessionConfigWithCallbacks.getSingleCameraCaptureCallbacks()).contains(
-                mockSingleCallback);
-
-        // Act.
-        boolean removedSingle = builder.removeCameraCaptureCallback(mockSingleCallback);
-        SessionConfig sessionConfigWithoutSingleCallback = builder.build();
-
-        // Assert.
-        assertThat(removedSingle).isTrue();
-        assertThat(sessionConfigWithoutSingleCallback.getSingleCameraCaptureCallbacks())
-                .doesNotContain(mockSingleCallback);
-
-        // Act.
-        boolean removedRepeating = builder.removeCameraCaptureCallback(mockRepeatingCallback);
-        SessionConfig sessionConfigWithoutCallbacks = builder.build();
-
-        // Assert.
-        assertThat(removedRepeating).isTrue();
-        assertThat(
-                sessionConfigWithoutCallbacks.getRepeatingCameraCaptureCallbacks()).doesNotContain(
-                mockRepeatingCallback);
-    }
-
-    @Test(expected = UnsupportedOperationException.class)
-    public void singleCameraCaptureCallbacks_areImmutable() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig configuration = builder.build();
-
-        configuration.getSingleCameraCaptureCallbacks().add(mock(CameraCaptureCallback.class));
-    }
-
-    @Test
-    public void builderAddErrorListener() {
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        SessionConfig.ErrorListener callback = mock(SessionConfig.ErrorListener.class);
-
-        builder.addErrorListener(callback);
-
-        SessionConfig config = builder.build();
-
-        assertThat(config.getErrorListeners()).contains(callback);
-    }
-
-    @Test
-    public void combineTwoSessionsCallbacks() {
-        SessionConfig.Builder builder0 = new SessionConfig.Builder();
-        CameraCaptureSession.StateCallback sessionCallback0 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraDevice.StateCallback deviceCallback0 = mock(CameraDevice.StateCallback.class);
-        CameraCaptureCallback repeatingCallback0 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback cameraCallback0 = mock(CameraCaptureCallback.class);
-        SessionConfig.ErrorListener errorListener0 = mock(SessionConfig.ErrorListener.class);
-        builder0.addSessionStateCallback(sessionCallback0);
-        builder0.addDeviceStateCallback(deviceCallback0);
-        builder0.addRepeatingCameraCaptureCallback(repeatingCallback0);
-        builder0.addCameraCaptureCallback(cameraCallback0);
-        builder0.addErrorListener(errorListener0);
-
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        CameraCaptureSession.StateCallback sessionCallback1 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraDevice.StateCallback deviceCallback1 = mock(CameraDevice.StateCallback.class);
-        CameraCaptureCallback repeatingCallback1 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback cameraCallback1 = mock(CameraCaptureCallback.class);
-        SessionConfig.ErrorListener errorListener1 = mock(SessionConfig.ErrorListener.class);
-        builder1.addSessionStateCallback(sessionCallback1);
-        builder1.addDeviceStateCallback(deviceCallback1);
-        builder1.addRepeatingCameraCaptureCallback(repeatingCallback1);
-        builder1.addCameraCaptureCallback(cameraCallback1);
-        builder1.addErrorListener(errorListener1);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder0.build());
-        validatingBuilder.add(builder1.build());
-
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        assertThat(sessionConfig.getSessionStateCallbacks())
-                .containsExactly(sessionCallback0, sessionCallback1);
-        assertThat(sessionConfig.getDeviceStateCallbacks())
-                .containsExactly(deviceCallback0, deviceCallback1);
-        assertThat(sessionConfig.getRepeatingCameraCaptureCallbacks())
-                .containsExactly(
-                        repeatingCallback0, cameraCallback0, repeatingCallback1, cameraCallback1);
-        assertThat(sessionConfig.getSingleCameraCaptureCallbacks())
-                .containsExactly(cameraCallback0, cameraCallback1);
-        assertThat(sessionConfig.getErrorListeners()).containsExactly(errorListener0,
-                errorListener1);
-    }
-
-    @Test
-    public void combineTwoSessionsTagsValid() {
-        SessionConfig session0 = createSessionConfigWithTag("TEST00", 0);
-        SessionConfig session1 = createSessionConfigWithTag("TEST01", "String");
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(session0);
-        validatingBuilder.add(session1);
-
-        SessionConfig sessionCombined = validatingBuilder.build();
-
-        assertThat(validatingBuilder.isValid()).isTrue();
-
-        TagBundle tag = sessionCombined.getRepeatingCaptureConfig().getTagBundle();
-
-        assertThat(tag.getTag("TEST00")).isEqualTo(0);
-        assertThat(tag.getTag("TEST01")).isEqualTo("String");
-    }
-
-    @Test
-    public void builderChange_doNotChangeEarlierBuiltInstance() {
-        // 1. Arrange
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback2 = mock(CameraCaptureCallback.class);
-        DeferrableSurface deferrableSurface1 = mock(DeferrableSurface.class);
-        DeferrableSurface deferrableSurface2 = mock(DeferrableSurface.class);
-        CameraDevice.StateCallback deviceStateCallback1 = mock(CameraDevice.StateCallback.class);
-        CameraDevice.StateCallback deviceStateCallback2 = mock(CameraDevice.StateCallback.class);
-        CameraCaptureSession.StateCallback sessionCallback1 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraCaptureSession.StateCallback sessionCallback2 =
-                mock(CameraCaptureSession.StateCallback.class);
-        SessionConfig.ErrorListener errorListener1 = mock(SessionConfig.ErrorListener.class);
-        SessionConfig.ErrorListener errorListener2 = mock(SessionConfig.ErrorListener.class);
-        Range<Integer> fpsRange1 = new Range<>(30, 30);
-        Range<Integer> fpsRange2 = new Range<>(15, 30);
-        MutableOptionsBundle optionsBundle1 = MutableOptionsBundle.create();
-        optionsBundle1.insertOption(OPTION, 1);
-        MutableOptionsBundle optionsBundle2 = MutableOptionsBundle.create();
-        optionsBundle2.insertOption(OPTION, 2);
-        int template1 = CameraDevice.TEMPLATE_PREVIEW;
-        int template2 = CameraDevice.TEMPLATE_RECORD;
-
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        builder.addSurface(deferrableSurface1);
-        builder.setExpectedFrameRateRange(fpsRange1);
-        builder.addCameraCaptureCallback(callback1);
-        builder.addRepeatingCameraCaptureCallback(callback1);
-        builder.addDeviceStateCallback(deviceStateCallback1);
-        builder.addSessionStateCallback(sessionCallback1);
-        builder.setTemplateType(template1);
-        builder.addImplementationOptions(optionsBundle1);
-        builder.addErrorListener(errorListener1);
-        SessionConfig sessionConfig = builder.build();
-
-        // 2. Act
-        // builder change should not affect the instance built earlier.
-        builder.addSurface(deferrableSurface2);
-        builder.setExpectedFrameRateRange(fpsRange2);
-        builder.addCameraCaptureCallback(callback2);
-        builder.addRepeatingCameraCaptureCallback(callback2);
-        builder.addDeviceStateCallback(deviceStateCallback2);
-        builder.addSessionStateCallback(sessionCallback2);
-        builder.setTemplateType(template2);
-        builder.addImplementationOptions(optionsBundle2);
-        builder.addErrorListener(errorListener2);
-
-        // 3. Verify
-        assertThat(sessionConfig.getSurfaces()).containsExactly(deferrableSurface1);
-        assertThat(sessionConfig.getExpectedFrameRateRange()).isEqualTo(fpsRange1);
-        assertThat(sessionConfig.getSingleCameraCaptureCallbacks()).containsExactly(callback1);
-        assertThat(sessionConfig.getRepeatingCaptureConfig().getCameraCaptureCallbacks())
-                .containsExactly(callback1);
-        assertThat(sessionConfig.getDeviceStateCallbacks()).containsExactly(deviceStateCallback1);
-        assertThat(sessionConfig.getSessionStateCallbacks()).containsExactly(sessionCallback1);
-        assertThat(sessionConfig.getTemplateType()).isEqualTo(template1);
-        assertThat(sessionConfig.getImplementationOptions().retrieveOption(OPTION)).isEqualTo(1);
-        assertThat(sessionConfig.getErrorListeners()).containsExactly(errorListener1);
-    }
-
-    @Test
-    public void validatingBuilderChange_doNotChangeEarlierBuiltInstance() {
-        // 1. Arrange
-        CameraCaptureCallback callback1 = mock(CameraCaptureCallback.class);
-        CameraCaptureCallback callback2 = mock(CameraCaptureCallback.class);
-        DeferrableSurface deferrableSurface1 = mock(DeferrableSurface.class);
-        DeferrableSurface deferrableSurface2 = mock(DeferrableSurface.class);
-        CameraDevice.StateCallback deviceStateCallback1 = mock(CameraDevice.StateCallback.class);
-        CameraDevice.StateCallback deviceStateCallback2 = mock(CameraDevice.StateCallback.class);
-        CameraCaptureSession.StateCallback sessionCallback1 =
-                mock(CameraCaptureSession.StateCallback.class);
-        CameraCaptureSession.StateCallback sessionCallback2 =
-                mock(CameraCaptureSession.StateCallback.class);
-        SessionConfig.ErrorListener errorListener1 = mock(SessionConfig.ErrorListener.class);
-        SessionConfig.ErrorListener errorListener2 = mock(SessionConfig.ErrorListener.class);
-        Range<Integer> fpsRange1 = new Range<>(30, 30);
-        Range<Integer> fpsRange2 = new Range<>(15, 30);
-        MutableOptionsBundle optionsBundle1 = MutableOptionsBundle.create();
-        optionsBundle1.insertOption(OPTION, 1);
-        MutableOptionsBundle optionsBundle2 = MutableOptionsBundle.create();
-        optionsBundle2.insertOption(OPTION, 2);
-        int template1 = CameraDevice.TEMPLATE_PREVIEW;
-        int template2 = CameraDevice.TEMPLATE_RECORD;
-
-        SessionConfig.Builder builder = new SessionConfig.Builder();
-        builder.addSurface(deferrableSurface1);
-        builder.setExpectedFrameRateRange(fpsRange1);
-        builder.addCameraCaptureCallback(callback1);
-        builder.addRepeatingCameraCaptureCallback(callback1);
-        builder.addDeviceStateCallback(deviceStateCallback1);
-        builder.addSessionStateCallback(sessionCallback1);
-        builder.setTemplateType(template1);
-        builder.addImplementationOptions(optionsBundle1);
-        builder.addErrorListener(errorListener1);
-
-        SessionConfig.ValidatingBuilder validatingBuilder = new SessionConfig.ValidatingBuilder();
-        validatingBuilder.add(builder.build());
-        SessionConfig sessionConfig = validatingBuilder.build();
-
-        // 2. Act
-        // add another SessionConfig to ValidatingBuilder. This should not affect the
-        // instance built earlier.
-        SessionConfig.Builder builder2 = new SessionConfig.Builder();
-        builder2.addSurface(deferrableSurface2);
-        builder2.setExpectedFrameRateRange(fpsRange2);
-        builder2.addCameraCaptureCallback(callback2);
-        builder2.addRepeatingCameraCaptureCallback(callback2);
-        builder2.addDeviceStateCallback(deviceStateCallback2);
-        builder2.addSessionStateCallback(sessionCallback2);
-        builder2.setTemplateType(template2);
-        builder2.addImplementationOptions(optionsBundle2);
-        builder2.addErrorListener(errorListener2);
-        validatingBuilder.add(builder2.build());
-
-        // 3. Verify
-        assertThat(sessionConfig.getSurfaces()).containsExactly(deferrableSurface1);
-        assertThat(sessionConfig.getExpectedFrameRateRange()).isEqualTo(fpsRange1);
-        assertThat(sessionConfig.getSingleCameraCaptureCallbacks()).containsExactly(callback1);
-        assertThat(sessionConfig.getRepeatingCaptureConfig().getCameraCaptureCallbacks())
-                .containsExactly(callback1);
-        assertThat(sessionConfig.getDeviceStateCallbacks()).containsExactly(deviceStateCallback1);
-        assertThat(sessionConfig.getSessionStateCallbacks()).containsExactly(sessionCallback1);
-        assertThat(sessionConfig.getTemplateType()).isEqualTo(template1);
-        assertThat(sessionConfig.getImplementationOptions().retrieveOption(OPTION)).isEqualTo(1);
-        assertThat(sessionConfig.getErrorListeners()).containsExactly(errorListener1);
-    }
-
-    private SessionConfig createSessionConfigWithTag(String key, Object tagValue) {
-        SessionConfig.Builder builder1 = new SessionConfig.Builder();
-        builder1.addSurface(mMockSurface1);
-        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW);
-        builder1.addTag(key, tagValue);
-
-        return builder1.build();
-    }
-}
diff --git a/camera/camera-core/src/test/java/androidx/camera/core/impl/CaptureConfigTest.kt b/camera/camera-core/src/test/java/androidx/camera/core/impl/CaptureConfigTest.kt
new file mode 100644
index 00000000000..96db28e3dbd
--- /dev/null
+++ b/camera/camera-core/src/test/java/androidx/camera/core/impl/CaptureConfigTest.kt
@@ -0,0 +1,386 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.camera.core.impl
+
+import android.hardware.camera2.CameraDevice
+import android.os.Build
+import android.util.Range
+import androidx.camera.core.impl.Config.Option
+import androidx.camera.core.impl.Config.OptionPriority
+import androidx.camera.testing.impl.DeferrableSurfacesUtil
+import com.google.common.collect.Lists
+import com.google.common.truth.Truth.assertThat
+import java.util.Arrays
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import org.robolectric.annotation.internal.DoNotInstrument
+
+@RunWith(RobolectricTestRunner::class)
+@DoNotInstrument
+@Config(minSdk = Build.VERSION_CODES.LOLLIPOP)
+class CaptureConfigTest {
+    private var mMockSurface0: DeferrableSurface? = null
+    @Before
+    fun setup() {
+        mMockSurface0 = mock(DeferrableSurface::class.java)
+    }
+
+    @Test
+    fun builderSetTemplate() {
+        val builder = CaptureConfig.Builder()
+
+        builder.templateType = CameraDevice.TEMPLATE_PREVIEW
+        val captureConfig = builder.build()
+
+        assertThat(captureConfig.templateType).isEqualTo(CameraDevice.TEMPLATE_PREVIEW)
+    }
+
+    @Test
+    fun builderNotSetTemplate() {
+        val builder = CaptureConfig.Builder()
+
+        val captureConfig = builder.build()
+
+        assertThat(captureConfig.templateType).isEqualTo(CaptureConfig.TEMPLATE_TYPE_NONE)
+    }
+
+    @Test
+    fun builderAddSurface() {
+        val builder = CaptureConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        val captureConfig = builder.build()
+
+        val surfaces = captureConfig.surfaces
+
+        assertThat(surfaces).hasSize(1)
+        assertThat(surfaces).contains(mMockSurface0)
+    }
+
+    @Test
+    fun builderRemoveSurface() {
+        val builder = CaptureConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        builder.removeSurface(mMockSurface0!!)
+        val captureConfig = builder.build()
+
+        val surfaces = DeferrableSurfacesUtil.surfaceList(captureConfig.surfaces)
+        assertThat(surfaces).isEmpty()
+    }
+
+    @Test
+    fun builderClearSurface() {
+        val builder = CaptureConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        builder.clearSurfaces()
+        val captureConfig = builder.build()
+
+        val surfaces = DeferrableSurfacesUtil.surfaceList(captureConfig.surfaces)
+        assertThat(surfaces.size).isEqualTo(0)
+    }
+
+    @Test
+    fun builderAddOption() {
+        val builder = CaptureConfig.Builder()
+
+        val options = MutableOptionsBundle.create()
+        options.insertOption(OPTION, 1)
+        builder.addImplementationOptions(options)
+        val captureConfig = builder.build()
+
+        val config = captureConfig.implementationOptions
+
+        assertThat(config.containsOption(OPTION)).isTrue()
+        assertThat(config.retrieveOption(OPTION)).isEqualTo(1)
+    }
+
+    @Test
+    fun addOption_priorityIsKept() {
+        val builder = CaptureConfig.Builder()
+
+        val options = MutableOptionsBundle.create()
+        options.insertOption(OPTION, OptionPriority.REQUIRED, 1)
+        builder.addImplementationOptions(options)
+        val captureConfig = builder.build()
+
+        val config = captureConfig.implementationOptions
+
+        assertThat(config.containsOption(OPTION)).isTrue()
+        assertThat(config.retrieveOption(OPTION)).isEqualTo(1)
+        assertThat(config.getOptionPriority(OPTION)).isEqualTo(OptionPriority.REQUIRED)
+    }
+
+    @Test
+    fun builderSetUseTargetedSurface() {
+        val builder = CaptureConfig.Builder()
+
+        builder.isUseRepeatingSurface = true
+        val captureConfig = builder.build()
+
+        assertThat(captureConfig.isUseRepeatingSurface).isTrue()
+    }
+
+    @Test
+    fun builderAddMultipleCameraCaptureCallbacks() {
+        val builder = CaptureConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+
+        builder.addCameraCaptureCallback(callback0)
+        builder.addCameraCaptureCallback(callback1)
+        val configuration = builder.build()
+
+        assertThat(configuration.cameraCaptureCallbacks).containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddAllCameraCaptureCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callbacks: List<CameraCaptureCallback> = Lists.newArrayList(callback0, callback1)
+
+        builder.addAllRepeatingCameraCaptureCallbacks(callbacks)
+        val configuration = builder.build()
+
+        assertThat(configuration.repeatingCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddImplementationMultiValue() {
+        val builder = CaptureConfig.Builder()
+
+        val obj1 = Any()
+        val fakeMultiValueSet1 = FakeMultiValueSet()
+        fakeMultiValueSet1.addAll(Arrays.asList(obj1))
+        val fakeConfig1 = MutableOptionsBundle.create()
+        fakeConfig1.insertOption(FAKE_MULTI_VALUE_SET_OPTION, fakeMultiValueSet1)
+        builder.addImplementationOptions(fakeConfig1)
+
+        val obj2 = Any()
+        val fakeMultiValueSet2 = FakeMultiValueSet()
+        fakeMultiValueSet2.addAll(Arrays.asList(obj2))
+        val fakeConfig2 = MutableOptionsBundle.create()
+        fakeConfig2.insertOption(FAKE_MULTI_VALUE_SET_OPTION, fakeMultiValueSet2)
+        builder.addImplementationOptions(fakeConfig2)
+
+        val captureConfig = builder.build()
+
+        val fakeMultiValueSet =
+            captureConfig.implementationOptions.retrieveOption(
+                FAKE_MULTI_VALUE_SET_OPTION
+            )
+
+        assertThat(fakeMultiValueSet).isNotNull()
+        assertThat(fakeMultiValueSet!!.allItems).containsExactly(obj1, obj2)
+    }
+
+    @Test
+    fun builderAddSingleImplementationOption() {
+        val builder = CaptureConfig.Builder()
+
+        builder.addImplementationOption(CaptureConfig.OPTION_ROTATION, 90)
+
+        val captureConfig = builder.build()
+
+        assertThat(
+            captureConfig.implementationOptions.retrieveOption(
+                CaptureConfig.OPTION_ROTATION
+            )
+        ).isEqualTo(90)
+    }
+
+    @Test
+    fun builderFromPrevious_containsCameraCaptureCallbacks() {
+        var builder = CaptureConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        builder.addCameraCaptureCallback(callback0)
+        builder.addCameraCaptureCallback(callback1)
+        builder = CaptureConfig.Builder.from(builder.build())
+        val callback2 = mock(
+            CameraCaptureCallback::class.java
+        )
+
+        builder.addCameraCaptureCallback(callback2)
+        val configuration = builder.build()
+
+        assertThat(configuration.cameraCaptureCallbacks)
+            .containsExactly(callback0, callback1, callback2)
+    }
+
+    @Test
+    fun builderRemoveCameraCaptureCallback_returnsFalseIfNotAdded() {
+        val mockCallback = mock(
+            CameraCaptureCallback::class.java
+        )
+        val builder = CaptureConfig.Builder()
+
+        assertThat(builder.removeCameraCaptureCallback(mockCallback)).isFalse()
+    }
+
+    @Test
+    fun builderRemoveCameraCaptureCallback_removesAddedCallback() {
+        // Arrange.
+        val mockCallback = mock(
+            CameraCaptureCallback::class.java
+        )
+        val builder = CaptureConfig.Builder()
+
+        // Act.
+        builder.addCameraCaptureCallback(mockCallback)
+        val configWithCallback = builder.build()
+
+        // Assert.
+        assertThat(configWithCallback.cameraCaptureCallbacks).contains(mockCallback)
+
+        // Act.
+        val removedCallback = builder.removeCameraCaptureCallback(mockCallback)
+        val configWithoutCallback = builder.build()
+
+        // Assert.
+        assertThat(removedCallback).isTrue()
+        assertThat(configWithoutCallback.cameraCaptureCallbacks).doesNotContain(mockCallback)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun cameraCaptureCallbacks_areImmutable() {
+        val builder = CaptureConfig.Builder()
+        val configuration = builder.build()
+
+        configuration.cameraCaptureCallbacks.add(
+            mock(
+                CameraCaptureCallback::class.java
+            )
+        )
+    }
+
+    @Test
+    fun postviewEnabledDefaultIsFalse() {
+        // 1. Arrange / Act
+        val captureConfig = CaptureConfig.Builder().build()
+
+        // 3. Assert
+        assertThat(captureConfig.isPostviewEnabled).isFalse()
+    }
+
+    @Test
+    fun canSetPostviewEnabled() {
+        // 1. Arrange
+        val builder = CaptureConfig.Builder()
+
+        // 2. Act
+        builder.setPostviewEnabled(true)
+        val captureConfig = builder.build()
+
+        // 3. Assert
+        assertThat(captureConfig.isPostviewEnabled).isTrue()
+    }
+
+    @Test
+    fun builderChange_doNotChangeEarlierBuiltInstance() {
+        // 1. Arrange
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback2 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val deferrableSurface1 = mock(
+            DeferrableSurface::class.java
+        )
+        val deferrableSurface2 = mock(
+            DeferrableSurface::class.java
+        )
+        val fpsRange1 = Range(30, 30)
+        val fpsRange2 = Range(15, 30)
+        val optionValue1 = 1
+        val optionValue2 = 2
+        val tagValue1 = 1
+        val tagValue2 = 2
+        val template1 = CameraDevice.TEMPLATE_PREVIEW
+        val template2 = CameraDevice.TEMPLATE_RECORD
+
+        val builder = CaptureConfig.Builder()
+        builder.addSurface(deferrableSurface1)
+        builder.setExpectedFrameRateRange(fpsRange1)
+        builder.addCameraCaptureCallback(callback1)
+        builder.templateType = template1
+        builder.addTag("KEY", tagValue1)
+        builder.addImplementationOption(OPTION, optionValue1)
+        val captureConfig = builder.build()
+
+        // 2. Act
+        // builder change should not affect the instance built earlier.
+        builder.addSurface(deferrableSurface2)
+        builder.setExpectedFrameRateRange(fpsRange2)
+        builder.addCameraCaptureCallback(callback2)
+        builder.templateType = template2
+        builder.addTag("KEY", tagValue2)
+        builder.addImplementationOption(OPTION, optionValue2)
+
+        // 3. Verify
+        assertThat(captureConfig.surfaces).containsExactly(deferrableSurface1)
+        assertThat(captureConfig.expectedFrameRateRange).isEqualTo(fpsRange1)
+        assertThat(captureConfig.cameraCaptureCallbacks).containsExactly(callback1)
+        assertThat(captureConfig.templateType).isEqualTo(template1)
+        assertThat(captureConfig.tagBundle.getTag("KEY")).isEqualTo(tagValue1)
+        assertThat(captureConfig.implementationOptions.retrieveOption(OPTION))
+            .isEqualTo(optionValue1)
+    }
+
+    /**
+     * A fake [MultiValueSet].
+     */
+    internal class FakeMultiValueSet : MultiValueSet<Any?>() {
+        override fun clone(): MultiValueSet<Any?> {
+            val multiValueSet = FakeMultiValueSet()
+            multiValueSet.addAll(allItems)
+            return multiValueSet
+        }
+    }
+
+    companion object {
+        private val OPTION = Option.create<Int>(
+            "camerax.test.option_0", Int::class.java
+        )
+
+        private val FAKE_MULTI_VALUE_SET_OPTION: Option<FakeMultiValueSet> =
+            Option.create(
+                "option.fakeMultiValueSet.1",
+                FakeMultiValueSet::class.java
+            )
+    }
+}
diff --git a/camera/camera-core/src/test/java/androidx/camera/core/impl/SessionConfigTest.kt b/camera/camera-core/src/test/java/androidx/camera/core/impl/SessionConfigTest.kt
new file mode 100644
index 00000000000..192922d6c6b
--- /dev/null
+++ b/camera/camera-core/src/test/java/androidx/camera/core/impl/SessionConfigTest.kt
@@ -0,0 +1,1232 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package androidx.camera.core.impl
+
+import android.hardware.camera2.CameraCaptureSession
+import android.hardware.camera2.CameraDevice
+import android.hardware.camera2.params.SessionConfiguration
+import android.os.Build
+import android.util.Range
+import android.view.Surface
+import androidx.camera.camera2.impl.Camera2ImplConfig
+import androidx.camera.core.ImageCapture
+import androidx.camera.core.Preview
+import androidx.camera.core.impl.Config.Option
+import androidx.camera.core.impl.SessionConfig.ValidatingBuilder
+import androidx.camera.testing.impl.DeferrableSurfacesUtil
+import androidx.camera.testing.impl.fakes.FakeMultiValueSet
+import com.google.common.collect.Lists
+import com.google.common.truth.Truth.assertThat
+import java.util.Arrays
+import org.junit.After
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.mockito.Mockito.mock
+import org.robolectric.RobolectricTestRunner
+import org.robolectric.annotation.Config
+import org.robolectric.annotation.internal.DoNotInstrument
+
+@RunWith(RobolectricTestRunner::class)
+@DoNotInstrument
+@Config(minSdk = Build.VERSION_CODES.LOLLIPOP)
+class SessionConfigTest {
+    private var mMockSurface0: DeferrableSurface? = null
+    private var mMockSurface1: DeferrableSurface? = null
+
+    @Before
+    fun setup() {
+        mMockSurface0 = ImmediateSurface(mock(Surface::class.java))
+        mMockSurface1 = ImmediateSurface(mock(Surface::class.java))
+    }
+
+    @After
+    fun tearDown() {
+        mMockSurface0!!.close()
+        mMockSurface1!!.close()
+    }
+
+    @Test
+    fun builderSetTemplate() {
+        val builder = SessionConfig.Builder()
+
+        builder.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfig = builder.build()
+
+        assertThat(sessionConfig.templateType).isEqualTo(CameraDevice.TEMPLATE_PREVIEW)
+    }
+
+    @Test
+    fun builderAddSurface() {
+        val builder = SessionConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        val sessionConfig = builder.build()
+
+        val surfaces = sessionConfig.surfaces
+        val outputConfigs = sessionConfig.outputConfigs
+
+        assertThat(surfaces).hasSize(1)
+        assertThat(surfaces).contains(mMockSurface0)
+        assertThat(outputConfigs).hasSize(1)
+        assertThat(outputConfigs[0]!!.surface).isEqualTo(mMockSurface0)
+        assertThat(outputConfigs[0]!!.sharedSurfaces).isEmpty()
+        assertThat(outputConfigs[0]!!.physicalCameraId).isNull()
+        assertThat(outputConfigs[0]!!.surfaceGroupId)
+            .isEqualTo(SessionConfig.OutputConfig.SURFACE_GROUP_ID_NONE)
+    }
+
+    @Test
+    fun builderAddOutputConfig() {
+        val builder = SessionConfig.Builder()
+        val sharedSurface1: DeferrableSurface = ImmediateSurface(
+            mock(
+                Surface::class.java
+            )
+        )
+        val sharedSurface2: DeferrableSurface = ImmediateSurface(
+            mock(
+                Surface::class.java
+            )
+        )
+        val outputConfig = SessionConfig.OutputConfig.builder(
+            mMockSurface0!!
+        )
+            .setSurfaceGroupId(1)
+            .setSharedSurfaces(Arrays.asList(sharedSurface1, sharedSurface2))
+            .setPhysicalCameraId("4")
+            .build()
+
+        builder.addOutputConfig(outputConfig)
+        val sessionConfig = builder.build()
+
+        val surfaces = sessionConfig.surfaces
+        val outputConfigs = sessionConfig.outputConfigs
+
+        assertThat(surfaces).containsExactly(mMockSurface0, sharedSurface1, sharedSurface2)
+        assertThat(outputConfigs).hasSize(1)
+        assertThat(outputConfigs[0]!!.surface).isEqualTo(mMockSurface0)
+        assertThat(outputConfigs[0]!!.sharedSurfaces)
+            .containsExactly(sharedSurface1, sharedSurface2)
+        assertThat(outputConfigs[0]!!.surfaceGroupId).isEqualTo(1)
+        assertThat(outputConfigs[0]!!.physicalCameraId).isEqualTo("4")
+    }
+
+    @Test
+    fun builderAddNonRepeatingSurface() {
+        val builder = SessionConfig.Builder()
+
+        builder.addNonRepeatingSurface(mMockSurface0!!)
+        val sessionConfig = builder.build()
+
+        val surfaces = sessionConfig.surfaces
+        val outputConfigs = sessionConfig.outputConfigs
+        val repeatingSurfaces =
+            sessionConfig.repeatingCaptureConfig.surfaces
+
+        assertThat(surfaces).containsExactly(mMockSurface0)
+        assertThat(outputConfigs).hasSize(1)
+        assertThat(outputConfigs[0]!!.surface).isEqualTo(mMockSurface0)
+        assertThat(repeatingSurfaces).isEmpty()
+        assertThat(repeatingSurfaces).doesNotContain(mMockSurface0)
+    }
+
+    @Test
+    fun builderAddSurfaceContainsRepeatingSurface() {
+        val builder = SessionConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        builder.addNonRepeatingSurface(mMockSurface1!!)
+        val sessionConfig = builder.build()
+
+        val surfaces = DeferrableSurfacesUtil.surfaceList(sessionConfig.surfaces)
+        val repeatingSurfaces = DeferrableSurfacesUtil.surfaceList(
+            sessionConfig.repeatingCaptureConfig.surfaces
+        )
+
+        assertThat(surfaces.size).isAtLeast(repeatingSurfaces.size)
+        assertThat(surfaces).containsAtLeastElementsIn(repeatingSurfaces)
+    }
+
+    @Test
+    fun builderRemoveSurface() {
+        val builder = SessionConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        builder.addSurface(mMockSurface1!!)
+        builder.removeSurface(mMockSurface0!!)
+        val sessionConfig = builder.build()
+
+        assertThat(sessionConfig.surfaces).containsExactly(mMockSurface1)
+        assertThat(sessionConfig.outputConfigs).hasSize(1)
+        assertThat(sessionConfig.outputConfigs[0].surface).isEqualTo(mMockSurface1)
+    }
+
+    @Test
+    fun builderClearSurface() {
+        val builder = SessionConfig.Builder()
+
+        builder.addSurface(mMockSurface0!!)
+        builder.clearSurfaces()
+        val sessionConfig = builder.build()
+
+        assertThat(sessionConfig.surfaces).isEmpty()
+        assertThat(sessionConfig.outputConfigs).isEmpty()
+    }
+
+    @Test
+    fun builderAddOption() {
+        val builder = SessionConfig.Builder()
+
+        val options = MutableOptionsBundle.create()
+        options.insertOption(OPTION, 1)
+        builder.addImplementationOptions(options)
+        val sessionConfig = builder.build()
+
+        val config = sessionConfig.implementationOptions
+
+        assertThat(config.containsOption(OPTION)).isTrue()
+        assertThat(config.retrieveOption(OPTION)).isEqualTo(1)
+    }
+
+    @Test
+    fun builderDefaultSessionTypeIsRegular() {
+        val builder = SessionConfig.Builder()
+        val sessionConfig = builder.build()
+        assertThat(sessionConfig.sessionType == SessionConfiguration.SESSION_REGULAR)
+    }
+
+    @Test
+    fun builderSetSessionType() {
+        val builder = SessionConfig.Builder()
+            .setSessionType(2)
+        val sessionConfig = builder.build()
+        assertThat(sessionConfig.sessionType == 2)
+    }
+
+    @Test
+    fun builderSetPostviewSurface() {
+        val builder = SessionConfig.Builder()
+            .setPostviewSurface(mMockSurface0!!)
+        val sessionConfig = builder.build()
+        assertThat(sessionConfig.postviewOutputConfig!!.surface).isEqualTo(mMockSurface0)
+    }
+
+    @Test
+    fun prioritizeTemplateType_previewHigherThanUnsupportedType() {
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfigPreview = builderPreview.build()
+        val builderManual = SessionConfig.Builder()
+        builderManual.setTemplateType(CameraDevice.TEMPLATE_MANUAL)
+        val sessionConfigManual = builderManual.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+        validatingBuilder.add(sessionConfigManual)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().templateType).isEqualTo(
+            CameraDevice.TEMPLATE_PREVIEW
+        )
+    }
+
+    @Test
+    fun prioritizeTemplateType_recordHigherThanPreview() {
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfigPreview = builderPreview.build()
+        val builderRecord = SessionConfig.Builder()
+        builderRecord.setTemplateType(CameraDevice.TEMPLATE_RECORD)
+        val sessionConfigRecord = builderRecord.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+        validatingBuilder.add(sessionConfigRecord)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().templateType).isEqualTo(
+            CameraDevice.TEMPLATE_RECORD
+        )
+    }
+
+    @Test
+    fun prioritizeTemplateType_addZslFirst_zslHigherThanPreview() {
+        val builderZsl = SessionConfig.Builder()
+        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG)
+        val sessionConfigZsl = builderZsl.build()
+
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigZsl)
+        validatingBuilder.add(sessionConfigPreview)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().templateType).isEqualTo(
+            CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG
+        )
+    }
+
+    @Test
+    fun prioritizeTemplateType_addPreviewFirst_zslHigherThanPreview() {
+        val builderZsl = SessionConfig.Builder()
+        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG)
+        val sessionConfigZsl = builderZsl.build()
+
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+        validatingBuilder.add(sessionConfigZsl)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().templateType).isEqualTo(
+            CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG
+        )
+    }
+
+    @Test
+    fun setAndVerifyExpectedFrameRateRange_nullValue() {
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().expectedFrameRateRange).isEqualTo(
+            StreamSpec.FRAME_RATE_RANGE_UNSPECIFIED
+        )
+    }
+
+    @Test
+    fun setAndVerifyExpectedFrameRateRange_initialValue() {
+        val fpsRangeLow = Range(30, 45)
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        builderPreview.setExpectedFrameRateRange(fpsRangeLow)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().expectedFrameRateRange).isEqualTo(
+            fpsRangeLow
+        )
+    }
+
+    @Test
+    fun setAndVerifyExpectedFrameRateRange_sameValues() {
+        val fpsRangeLow = Range(30, 45)
+        val builderZsl = SessionConfig.Builder()
+        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG)
+        builderZsl.setExpectedFrameRateRange(fpsRangeLow)
+        val sessionConfigZsl = builderZsl.build()
+
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        builderPreview.setExpectedFrameRateRange(fpsRangeLow)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+        validatingBuilder.add(sessionConfigZsl)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        assertThat(validatingBuilder.build().expectedFrameRateRange).isEqualTo(
+            fpsRangeLow
+        )
+    }
+
+    @Test
+    fun setAndVerifyExpectedFrameRateRange_differentValues() {
+        val fpsRangeLow = Range(30, 45)
+        val fpsRangeHigh = Range(45, 60)
+        val builderZsl = SessionConfig.Builder()
+        builderZsl.setTemplateType(CameraDevice.TEMPLATE_ZERO_SHUTTER_LAG)
+        builderZsl.setExpectedFrameRateRange(fpsRangeLow)
+        val sessionConfigZsl = builderZsl.build()
+
+        val builderPreview = SessionConfig.Builder()
+        builderPreview.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        builderPreview.setExpectedFrameRateRange(fpsRangeHigh)
+        val sessionConfigPreview = builderPreview.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(sessionConfigPreview)
+        validatingBuilder.add(sessionConfigZsl)
+
+        assertThat(validatingBuilder.isValid).isFalse()
+    }
+
+    @Test
+    fun addImplementationOptionForStreamUseCase() {
+        val validatingBuilder = ValidatingBuilder()
+        assertThat(
+            !validatingBuilder.build().implementationOptions.containsOption(
+                Camera2ImplConfig.STREAM_USE_CASE_OPTION
+            )
+        )
+        validatingBuilder.addImplementationOption(Camera2ImplConfig.STREAM_USE_CASE_OPTION, 1L)
+        assertThat(
+            validatingBuilder.build().implementationOptions.retrieveOption(
+                Camera2ImplConfig.STREAM_USE_CASE_OPTION
+            ) == 1L
+        )
+    }
+
+    @Test
+    fun addDifferentNonDefaultSessionType() {
+        // 1. Arrange.
+        val validatingBuilder = ValidatingBuilder()
+        val sessionConfig1 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setSessionType(1).build()
+        val sessionConfig2 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setSessionType(2).build()
+
+        // 2. Act.
+        validatingBuilder.add(sessionConfig1)
+        validatingBuilder.add(sessionConfig2)
+
+        // 3. Assert.
+        assertThat(validatingBuilder.isValid).isFalse()
+    }
+
+    @Test
+    fun addDefaultAndThenNonDefaultSessionType() {
+        // 1. Arrange.
+        val sessionTypeToVerify = 2
+        val validatingBuilder = ValidatingBuilder()
+        val sessionConfig1 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW).build()
+        val sessionConfig2 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setSessionType(sessionTypeToVerify).build()
+
+        // 2. Act.
+        validatingBuilder.add(sessionConfig1)
+        validatingBuilder.add(sessionConfig2)
+
+        // 3. Assert.
+        assertThat(validatingBuilder.build().sessionType).isEqualTo(sessionTypeToVerify)
+        assertThat(validatingBuilder.isValid).isTrue()
+    }
+
+    @Test
+    fun addNonDefaultAndThenDefaultSessionType() {
+        // 1. Arrange.
+        val sessionTypeToVerify = 2
+        val validatingBuilder = ValidatingBuilder()
+        val sessionConfig1 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setSessionType(sessionTypeToVerify).build()
+        val sessionConfig2 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW).build()
+
+        // 2. Act.
+        validatingBuilder.add(sessionConfig1)
+        validatingBuilder.add(sessionConfig2)
+
+        // 3. Assert.
+        assertThat(validatingBuilder.build().sessionType).isEqualTo(sessionTypeToVerify)
+        assertThat(validatingBuilder.isValid).isTrue()
+    }
+
+    @Test
+    fun addPostviewSurfaceTo_validatingBuilder() {
+        // 1. Arrange.
+        val validatingBuilder = ValidatingBuilder()
+        val sessionConfig1 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setPostviewSurface(mMockSurface0!!)
+            .build()
+
+        // 2. Act.
+        validatingBuilder.add(sessionConfig1)
+
+        // 3. Assert.
+        assertThat(validatingBuilder.build().postviewOutputConfig!!.surface)
+            .isEqualTo(mMockSurface0)
+        assertThat(validatingBuilder.isValid).isTrue()
+    }
+
+    @Test
+    fun addDifferentPostviewSurfacesTo_validatingBuilder() {
+        // 1. Arrange.
+        val validatingBuilder = ValidatingBuilder()
+        val sessionConfig1 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setPostviewSurface(mMockSurface0!!)
+            .build()
+        val sessionConfig2 = SessionConfig.Builder()
+            .setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+            .setPostviewSurface(mMockSurface1!!)
+            .build()
+
+        // 2. Act.
+        validatingBuilder.add(sessionConfig1)
+        validatingBuilder.add(sessionConfig2)
+
+        // 3. Assert.
+        assertThat(validatingBuilder.isValid).isFalse()
+    }
+
+    @Test
+    fun conflictingOptions() {
+        val builder0 = SessionConfig.Builder()
+        val options0 = MutableOptionsBundle.create()
+        options0.insertOption(OPTION, 1)
+        builder0.addImplementationOptions(options0)
+        val config0 = builder0.build()
+
+        val builder1 = SessionConfig.Builder()
+        val options1 = MutableOptionsBundle.create()
+        options1.insertOption(OPTION, 2)
+        builder1.addImplementationOptions(options1)
+        val config1 = builder1.build()
+
+        val validatingBuilder = ValidatingBuilder()
+
+        validatingBuilder.add(config0)
+        validatingBuilder.add(config1)
+
+        assertThat(validatingBuilder.isValid).isFalse()
+    }
+
+    @Test
+    fun combineTwoSessionsValid() {
+        val builder0 = SessionConfig.Builder()
+        builder0.addSurface(mMockSurface0!!)
+        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options0 = MutableOptionsBundle.create()
+        options0.insertOption(OPTION, 1)
+        builder0.addImplementationOptions(options0)
+
+        val builder1 = SessionConfig.Builder()
+        builder1.addSurface(mMockSurface1!!)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options1 = MutableOptionsBundle.create()
+        options1.insertOption(OPTION_1, "test")
+        builder1.addImplementationOptions(options1)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder0.build())
+        validatingBuilder.add(builder1.build())
+
+        assertThat(validatingBuilder.isValid).isTrue()
+    }
+
+    @Test
+    fun combineTwoSessionsTemplate() {
+        val builder0 = SessionConfig.Builder()
+        builder0.addSurface(mMockSurface0!!)
+        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options0 = MutableOptionsBundle.create()
+        options0.insertOption(OPTION, 1)
+        builder0.addImplementationOptions(options0)
+
+        val builder1 = SessionConfig.Builder()
+        builder1.addSurface(mMockSurface1!!)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options1 = MutableOptionsBundle.create()
+        options1.insertOption(OPTION_1, "test")
+        builder1.addImplementationOptions(options1)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder0.build())
+        validatingBuilder.add(builder1.build())
+
+        val sessionConfig = validatingBuilder.build()
+
+        assertThat(sessionConfig.templateType).isEqualTo(CameraDevice.TEMPLATE_PREVIEW)
+    }
+
+    private fun createSurface(containerClass: Class<*>): DeferrableSurface {
+        val deferrableSurface: DeferrableSurface = ImmediateSurface(
+            mock(
+                Surface::class.java
+            )
+        )
+        deferrableSurface.setContainerClass(containerClass)
+        return deferrableSurface
+    }
+
+    @Test
+    fun combineTwoSessionsSurfaces() {
+        val previewSurface = createSurface(Preview::class.java)
+        val imageCaptureSurface = createSurface(ImageCapture::class.java)
+
+        val builder1 = SessionConfig.Builder()
+        builder1.addSurface(previewSurface)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+
+        val builder2 = SessionConfig.Builder()
+        builder2.addSurface(imageCaptureSurface)
+        builder2.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder1.build())
+        validatingBuilder.add(builder2.build())
+
+        val sessionConfig = validatingBuilder.build()
+
+        val surfaces = sessionConfig.surfaces
+        // Ensures the surfaces are all added and sorted correctly.
+        assertThat(surfaces).containsExactly(previewSurface, imageCaptureSurface).inOrder()
+    }
+
+    @Test
+    fun combineTwoSessionsOutputConfigs() {
+        val nonRepeatingSurface = mock(
+            DeferrableSurface::class.java
+        )
+
+        val builder0 = SessionConfig.Builder()
+        val outputConfig0 =
+            SessionConfig.OutputConfig.builder(mMockSurface0!!).build()
+        builder0.addOutputConfig(outputConfig0)
+        builder0.addNonRepeatingSurface(nonRepeatingSurface)
+        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+
+        val builder1 = SessionConfig.Builder()
+        val outputConfig1 =
+            SessionConfig.OutputConfig.builder(mMockSurface1!!).build()
+        builder1.addOutputConfig(outputConfig1)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder0.build())
+        validatingBuilder.add(builder1.build())
+
+        val sessionConfig = validatingBuilder.build()
+
+        val surfaces = sessionConfig.surfaces
+        assertThat(surfaces)
+            .containsExactly(mMockSurface0, mMockSurface1, nonRepeatingSurface)
+        assertThat(sessionConfig.outputConfigs).hasSize(3)
+        assertThat(sessionConfig.outputConfigs[0]).isEqualTo(outputConfig0)
+        assertThat(sessionConfig.outputConfigs[1].surface)
+            .isEqualTo(nonRepeatingSurface)
+        assertThat(sessionConfig.outputConfigs[2]).isEqualTo(outputConfig1)
+        // Should not contain the nonRepeatingSurface.
+        assertThat(sessionConfig.repeatingCaptureConfig.surfaces)
+            .containsExactly(mMockSurface0, mMockSurface1)
+    }
+
+    @Test
+    fun combineTwoSessionsOptions() {
+        val builder0 = SessionConfig.Builder()
+        builder0.addSurface(mMockSurface0!!)
+        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options0 = MutableOptionsBundle.create()
+        options0.insertOption(OPTION, 1)
+        builder0.addImplementationOptions(options0)
+
+        val builder1 = SessionConfig.Builder()
+        builder1.addSurface(mMockSurface1!!)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options1 = MutableOptionsBundle.create()
+        options1.insertOption(OPTION_1, "test")
+        builder1.addImplementationOptions(options1)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder0.build())
+        validatingBuilder.add(builder1.build())
+
+        val sessionConfig = validatingBuilder.build()
+
+        val config = sessionConfig.implementationOptions
+
+        assertThat(config.retrieveOption(OPTION)).isEqualTo(1)
+        assertThat(config.retrieveOption(OPTION_1)).isEqualTo("test")
+    }
+
+    @Test
+    fun combineTwoSessionsMultiValueSetValid() {
+        val option = Option.create<FakeMultiValueSet>(
+            "multiValueSet",
+            FakeMultiValueSet::class.java
+        )
+
+        val builder0 = SessionConfig.Builder()
+        builder0.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        val options0 = MutableOptionsBundle.create()
+        val multiValueSet0 = FakeMultiValueSet()
+        options0.insertOption(option, multiValueSet0)
+        builder0.addImplementationOptions(options0)
+        val config0 = builder0.build()
+
+        val builder1 = SessionConfig.Builder()
+        val options1 = MutableOptionsBundle.create()
+        val multiValueSet1 = FakeMultiValueSet()
+        options1.insertOption(option, multiValueSet1)
+        builder1.addImplementationOptions(options1)
+        val config1 = builder1.build()
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(config0)
+        validatingBuilder.add(config1)
+
+        assertThat(validatingBuilder.isValid).isTrue()
+    }
+
+    @Test
+    fun builderAddMultipleRepeatingCameraCaptureCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+
+        builder.addRepeatingCameraCaptureCallback(callback0)
+        builder.addRepeatingCameraCaptureCallback(callback1)
+        val configuration = builder.build()
+
+        assertThat(configuration.repeatingCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+        assertThat(configuration.singleCameraCaptureCallbacks)
+            .containsNoneOf(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddAllRepeatingCameraCaptureCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callbacks: List<CameraCaptureCallback> = Lists.newArrayList(callback0, callback1)
+
+        builder.addAllRepeatingCameraCaptureCallbacks(callbacks)
+        val configuration = builder.build()
+
+        assertThat(configuration.repeatingCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+        assertThat(configuration.singleCameraCaptureCallbacks)
+            .containsNoneOf(callback0, callback1)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun repeatingCameraCaptureCallbacks_areImmutable() {
+        val builder = SessionConfig.Builder()
+        val configuration = builder.build()
+
+        configuration.repeatingCameraCaptureCallbacks.add(
+            mock(
+                CameraCaptureCallback::class.java
+            )
+        )
+    }
+
+    @Test
+    fun builderAddMultipleDeviceStateCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val callback1 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+
+        builder.addDeviceStateCallback(callback0)
+        builder.addDeviceStateCallback(callback1)
+        val configuration = builder.build()
+
+        assertThat(configuration.deviceStateCallbacks).containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddAllDeviceStateCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val callback1 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val callbacks: List<CameraDevice.StateCallback> = Lists.newArrayList(callback0, callback1)
+
+        builder.addAllDeviceStateCallbacks(callbacks)
+        val configuration = builder.build()
+
+        assertThat(configuration.deviceStateCallbacks).containsExactly(callback0, callback1)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun deviceStateCallbacks_areImmutable() {
+        val builder = SessionConfig.Builder()
+        val configuration = builder.build()
+
+        configuration.deviceStateCallbacks.add(
+            mock(
+                CameraDevice.StateCallback::class.java
+            )
+        )
+    }
+
+    @Test
+    fun builderAddMultipleSessionStateCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val callback1 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+
+        builder.addSessionStateCallback(callback0)
+        builder.addSessionStateCallback(callback1)
+        val configuration = builder.build()
+
+        assertThat(configuration.sessionStateCallbacks).containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddAllSessionStateCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val callback1 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val callbacks: List<CameraCaptureSession.StateCallback> =
+            Lists.newArrayList(callback0, callback1)
+
+        builder.addAllSessionStateCallbacks(callbacks)
+        val configuration = builder.build()
+
+        assertThat(configuration.sessionStateCallbacks).containsExactly(callback0, callback1)
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun sessionStateCallbacks_areImmutable() {
+        val builder = SessionConfig.Builder()
+        val configuration = builder.build()
+
+        configuration.sessionStateCallbacks
+            .add(mock(CameraCaptureSession.StateCallback::class.java))
+    }
+
+    @Test
+    fun builderAddMultipleCameraCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+
+        builder.addCameraCaptureCallback(callback0)
+        builder.addCameraCaptureCallback(callback1)
+        val configuration = builder.build()
+
+        assertThat(configuration.singleCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+        assertThat(configuration.repeatingCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun builderAddAllCameraCallbacks() {
+        val builder = SessionConfig.Builder()
+        val callback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callbacks: List<CameraCaptureCallback> = Lists.newArrayList(callback0, callback1)
+
+        builder.addAllCameraCaptureCallbacks(callbacks)
+        val configuration = builder.build()
+
+        assertThat(configuration.singleCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+        assertThat(configuration.repeatingCameraCaptureCallbacks)
+            .containsExactly(callback0, callback1)
+    }
+
+    @Test
+    fun removeCameraCaptureCallback_returnsFalseIfNotAdded() {
+        val mockCallback = mock(
+            CameraCaptureCallback::class.java
+        )
+        val builder = SessionConfig.Builder()
+
+        assertThat(builder.removeCameraCaptureCallback(mockCallback)).isFalse()
+    }
+
+    @Test
+    fun canAddAndRemoveCameraCaptureCallback_withBuilder() {
+        // Arrange.
+        val mockRepeatingCallback = mock(
+            CameraCaptureCallback::class.java
+        )
+        val mockSingleCallback = mock(
+            CameraCaptureCallback::class.java
+        )
+        val builder = SessionConfig.Builder()
+
+        // Act.
+        builder.addRepeatingCameraCaptureCallback(mockRepeatingCallback)
+        builder.addCameraCaptureCallback(mockSingleCallback)
+        val sessionConfigWithCallbacks = builder.build()
+
+        // Assert.
+        assertThat(sessionConfigWithCallbacks.singleCameraCaptureCallbacks).contains(
+            mockSingleCallback
+        )
+        assertThat(sessionConfigWithCallbacks.singleCameraCaptureCallbacks).contains(
+            mockSingleCallback
+        )
+
+        // Act.
+        val removedSingle = builder.removeCameraCaptureCallback(mockSingleCallback)
+        val sessionConfigWithoutSingleCallback = builder.build()
+
+        // Assert.
+        assertThat(removedSingle).isTrue()
+        assertThat(sessionConfigWithoutSingleCallback.singleCameraCaptureCallbacks)
+            .doesNotContain(mockSingleCallback)
+
+        // Act.
+        val removedRepeating = builder.removeCameraCaptureCallback(mockRepeatingCallback)
+        val sessionConfigWithoutCallbacks = builder.build()
+
+        // Assert.
+        assertThat(removedRepeating).isTrue()
+        assertThat(
+            sessionConfigWithoutCallbacks.repeatingCameraCaptureCallbacks
+        ).doesNotContain(
+            mockRepeatingCallback
+        )
+    }
+
+    @Test(expected = UnsupportedOperationException::class)
+    fun singleCameraCaptureCallbacks_areImmutable() {
+        val builder = SessionConfig.Builder()
+        val configuration = builder.build()
+
+        configuration.singleCameraCaptureCallbacks.add(
+            mock(
+                CameraCaptureCallback::class.java
+            )
+        )
+    }
+
+    @Test
+    fun builderAddErrorListener() {
+        val builder = SessionConfig.Builder()
+        val callback = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+
+        builder.addErrorListener(callback)
+
+        val config = builder.build()
+
+        assertThat(config.errorListeners).contains(callback)
+    }
+
+    @Test
+    fun combineTwoSessionsCallbacks() {
+        val builder0 = SessionConfig.Builder()
+        val sessionCallback0 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val deviceCallback0 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val repeatingCallback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val cameraCallback0 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val errorListener0 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        builder0.addSessionStateCallback(sessionCallback0)
+        builder0.addDeviceStateCallback(deviceCallback0)
+        builder0.addRepeatingCameraCaptureCallback(repeatingCallback0)
+        builder0.addCameraCaptureCallback(cameraCallback0)
+        builder0.addErrorListener(errorListener0)
+
+        val builder1 = SessionConfig.Builder()
+        val sessionCallback1 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val deviceCallback1 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val repeatingCallback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val cameraCallback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val errorListener1 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        builder1.addSessionStateCallback(sessionCallback1)
+        builder1.addDeviceStateCallback(deviceCallback1)
+        builder1.addRepeatingCameraCaptureCallback(repeatingCallback1)
+        builder1.addCameraCaptureCallback(cameraCallback1)
+        builder1.addErrorListener(errorListener1)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder0.build())
+        validatingBuilder.add(builder1.build())
+
+        val sessionConfig = validatingBuilder.build()
+
+        assertThat(sessionConfig.sessionStateCallbacks)
+            .containsExactly(sessionCallback0, sessionCallback1)
+        assertThat(sessionConfig.deviceStateCallbacks)
+            .containsExactly(deviceCallback0, deviceCallback1)
+        assertThat(sessionConfig.repeatingCameraCaptureCallbacks)
+            .containsExactly(
+                repeatingCallback0, cameraCallback0, repeatingCallback1, cameraCallback1
+            )
+        assertThat(sessionConfig.singleCameraCaptureCallbacks)
+            .containsExactly(cameraCallback0, cameraCallback1)
+        assertThat(sessionConfig.errorListeners).containsExactly(
+            errorListener0,
+            errorListener1
+        )
+    }
+
+    @Test
+    fun combineTwoSessionsTagsValid() {
+        val session0 = createSessionConfigWithTag("TEST00", 0)
+        val session1 = createSessionConfigWithTag("TEST01", "String")
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(session0)
+        validatingBuilder.add(session1)
+
+        val sessionCombined = validatingBuilder.build()
+
+        assertThat(validatingBuilder.isValid).isTrue()
+
+        val tag = sessionCombined.repeatingCaptureConfig.tagBundle
+
+        assertThat(tag.getTag("TEST00")).isEqualTo(0)
+        assertThat(tag.getTag("TEST01")).isEqualTo("String")
+    }
+
+    @Test
+    fun builderChange_doNotChangeEarlierBuiltInstance() {
+        // 1. Arrange
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback2 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val deferrableSurface1 = mock(
+            DeferrableSurface::class.java
+        )
+        val deferrableSurface2 = mock(
+            DeferrableSurface::class.java
+        )
+        val deviceStateCallback1 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val deviceStateCallback2 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val sessionCallback1 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val sessionCallback2 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val errorListener1 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        val errorListener2 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        val fpsRange1 = Range(30, 30)
+        val fpsRange2 = Range(15, 30)
+        val optionsBundle1 = MutableOptionsBundle.create()
+        optionsBundle1.insertOption(OPTION, 1)
+        val optionsBundle2 = MutableOptionsBundle.create()
+        optionsBundle2.insertOption(OPTION, 2)
+        val template1 = CameraDevice.TEMPLATE_PREVIEW
+        val template2 = CameraDevice.TEMPLATE_RECORD
+
+        val builder = SessionConfig.Builder()
+        builder.addSurface(deferrableSurface1)
+        builder.setExpectedFrameRateRange(fpsRange1)
+        builder.addCameraCaptureCallback(callback1)
+        builder.addRepeatingCameraCaptureCallback(callback1)
+        builder.addDeviceStateCallback(deviceStateCallback1)
+        builder.addSessionStateCallback(sessionCallback1)
+        builder.setTemplateType(template1)
+        builder.addImplementationOptions(optionsBundle1)
+        builder.addErrorListener(errorListener1)
+        val sessionConfig = builder.build()
+
+        // 2. Act
+        // builder change should not affect the instance built earlier.
+        builder.addSurface(deferrableSurface2)
+        builder.setExpectedFrameRateRange(fpsRange2)
+        builder.addCameraCaptureCallback(callback2)
+        builder.addRepeatingCameraCaptureCallback(callback2)
+        builder.addDeviceStateCallback(deviceStateCallback2)
+        builder.addSessionStateCallback(sessionCallback2)
+        builder.setTemplateType(template2)
+        builder.addImplementationOptions(optionsBundle2)
+        builder.addErrorListener(errorListener2)
+
+        // 3. Verify
+        assertThat(sessionConfig.surfaces).containsExactly(deferrableSurface1)
+        assertThat(sessionConfig.expectedFrameRateRange).isEqualTo(fpsRange1)
+        assertThat(sessionConfig.singleCameraCaptureCallbacks).containsExactly(callback1)
+        assertThat(sessionConfig.repeatingCaptureConfig.cameraCaptureCallbacks)
+            .containsExactly(callback1)
+        assertThat(sessionConfig.deviceStateCallbacks).containsExactly(deviceStateCallback1)
+        assertThat(sessionConfig.sessionStateCallbacks).containsExactly(sessionCallback1)
+        assertThat(sessionConfig.templateType).isEqualTo(template1)
+        assertThat(sessionConfig.implementationOptions.retrieveOption(OPTION)).isEqualTo(1)
+        assertThat(sessionConfig.errorListeners).containsExactly(errorListener1)
+    }
+
+    @Test
+    fun validatingBuilderChange_doNotChangeEarlierBuiltInstance() {
+        // 1. Arrange
+        val callback1 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val callback2 = mock(
+            CameraCaptureCallback::class.java
+        )
+        val deferrableSurface1 = mock(
+            DeferrableSurface::class.java
+        )
+        val deferrableSurface2 = mock(
+            DeferrableSurface::class.java
+        )
+        val deviceStateCallback1 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val deviceStateCallback2 = mock(
+            CameraDevice.StateCallback::class.java
+        )
+        val sessionCallback1 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val sessionCallback2 =
+            mock(CameraCaptureSession.StateCallback::class.java)
+        val errorListener1 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        val errorListener2 = mock(
+            SessionConfig.ErrorListener::class.java
+        )
+        val fpsRange1 = Range(30, 30)
+        val fpsRange2 = Range(15, 30)
+        val optionsBundle1 = MutableOptionsBundle.create()
+        optionsBundle1.insertOption(OPTION, 1)
+        val optionsBundle2 = MutableOptionsBundle.create()
+        optionsBundle2.insertOption(OPTION, 2)
+        val template1 = CameraDevice.TEMPLATE_PREVIEW
+        val template2 = CameraDevice.TEMPLATE_RECORD
+
+        val builder = SessionConfig.Builder()
+        builder.addSurface(deferrableSurface1)
+        builder.setExpectedFrameRateRange(fpsRange1)
+        builder.addCameraCaptureCallback(callback1)
+        builder.addRepeatingCameraCaptureCallback(callback1)
+        builder.addDeviceStateCallback(deviceStateCallback1)
+        builder.addSessionStateCallback(sessionCallback1)
+        builder.setTemplateType(template1)
+        builder.addImplementationOptions(optionsBundle1)
+        builder.addErrorListener(errorListener1)
+
+        val validatingBuilder = ValidatingBuilder()
+        validatingBuilder.add(builder.build())
+        val sessionConfig = validatingBuilder.build()
+
+        // 2. Act
+        // add another SessionConfig to ValidatingBuilder. This should not affect the
+        // instance built earlier.
+        val builder2 = SessionConfig.Builder()
+        builder2.addSurface(deferrableSurface2)
+        builder2.setExpectedFrameRateRange(fpsRange2)
+        builder2.addCameraCaptureCallback(callback2)
+        builder2.addRepeatingCameraCaptureCallback(callback2)
+        builder2.addDeviceStateCallback(deviceStateCallback2)
+        builder2.addSessionStateCallback(sessionCallback2)
+        builder2.setTemplateType(template2)
+        builder2.addImplementationOptions(optionsBundle2)
+        builder2.addErrorListener(errorListener2)
+        validatingBuilder.add(builder2.build())
+
+        // 3. Verify
+        assertThat(sessionConfig.surfaces).containsExactly(deferrableSurface1)
+        assertThat(sessionConfig.expectedFrameRateRange).isEqualTo(fpsRange1)
+        assertThat(sessionConfig.singleCameraCaptureCallbacks).containsExactly(callback1)
+        assertThat(sessionConfig.repeatingCaptureConfig.cameraCaptureCallbacks)
+            .containsExactly(callback1)
+        assertThat(sessionConfig.deviceStateCallbacks).containsExactly(deviceStateCallback1)
+        assertThat(sessionConfig.sessionStateCallbacks).containsExactly(sessionCallback1)
+        assertThat(sessionConfig.templateType).isEqualTo(template1)
+        assertThat(sessionConfig.implementationOptions.retrieveOption(OPTION)).isEqualTo(1)
+        assertThat(sessionConfig.errorListeners).containsExactly(errorListener1)
+    }
+
+    private fun createSessionConfigWithTag(key: String, tagValue: Any): SessionConfig {
+        val builder1 = SessionConfig.Builder()
+        builder1.addSurface(mMockSurface1!!)
+        builder1.setTemplateType(CameraDevice.TEMPLATE_PREVIEW)
+        builder1.addTag(key, tagValue)
+
+        return builder1.build()
+    }
+
+    companion object {
+        private val OPTION = Option.create<Int>(
+            "camerax.test.option_0", Int::class.java
+        )
+        private val OPTION_1 = Option.create<String>(
+            "camerax.test.option_1", String::class.java
+        )
+    }
+}