### Question:
PerformanceCachingGoogleCloudStorage extends ForwardingGoogleCloudStorage { @Override public void deleteObjects(List<StorageResourceId> resourceIds) throws IOException { super.deleteObjects(resourceIds); for (StorageResourceId resourceId : resourceIds) { cache.removeItem(resourceId); } } PerformanceCachingGoogleCloudStorage(
      GoogleCloudStorage delegate, PerformanceCachingGoogleCloudStorageOptions options); @VisibleForTesting  PerformanceCachingGoogleCloudStorage(
      GoogleCloudStorage delegate,
      PrefixMappedItemCache cache); @Override WritableByteChannel create(StorageResourceId resourceId); @Override void deleteBuckets(List<String> bucketNames); @Override void deleteObjects(List<StorageResourceId> resourceIds); @Override List<GoogleCloudStorageItemInfo> listBucketInfo(); @Override List<String> listObjectNames(String bucketName, String objectNamePrefix); @Override List<String> listObjectNames(
      String bucketName, String objectNamePrefix, ListObjectOptions listOptions); @Override List<GoogleCloudStorageItemInfo> listObjectInfo(String bucketName, String objectNamePrefix); @Override List<GoogleCloudStorageItemInfo> listObjectInfo(
      String bucketName, String objectNamePrefix, ListObjectOptions listOptions); @Override ListPage<GoogleCloudStorageItemInfo> listObjectInfoPage(
      String bucketName, String objectNamePrefix, ListObjectOptions listOptions, String pageToken); @Override GoogleCloudStorageItemInfo getItemInfo(StorageResourceId resourceId); @Override List<GoogleCloudStorageItemInfo> getItemInfos(List<StorageResourceId> resourceIds); @Override List<GoogleCloudStorageItemInfo> updateItems(List<UpdatableItemInfo> itemInfoList); @Override void close(); @Override GoogleCloudStorageItemInfo composeObjects(
      List<StorageResourceId> sources, StorageResourceId destination, CreateObjectOptions options); @VisibleForTesting void invalidateCache();  }### Answer:
@Test public void testDeleteObjects() throws IOException { List<StorageResourceId> ids = Lists.newArrayList(ITEM_A_A.getResourceId(), ITEM_B_A.getResourceId()); cache.putItem(ITEM_A_A); cache.putItem(ITEM_B_A); cache.putItem(ITEM_B_B); gcs.deleteObjects(ids); verify(gcsDelegate).deleteObjects(eq(ids)); assertThat(cache.getAllItemsRaw()).containsExactly(ITEM_B_B); }