@Override
  public CompletableFuture<Void> downloadBlobAsync(BlobId blobId, OutputStream outputStream) {
    CompletableFuture<Void> completableFuture = new CompletableFuture<>();
    FutureUtils.completeFromCallable(completableFuture, () -> {
      downloadBlob(blobId, outputStream);
      return null;
    });
    return completableFuture;
  }
Instantiate {@link LatchBasedInMemoryCloudDestination}.
@param blobIdsToTrack a list of blobs that {@link LatchBasedInMemoryCloudDestination} tracks.
@param azureReplicationFeedType {@link AzureReplicationFeed.FeedType} object.
ambry-vcr/src/test/java/com/github/ambry/vcr/LatchBasedInMemoryCloudDestination.java