@Override
        public void onBlobDeleted(String blobId, String serviceId, Account account, Container container) {
          deletedBlobs.add(blobId);
          deletesDoneLatch.get().countDown();
        }
Test that stitched blobs are usable by the other router methods.
@throws Exception
ambry-router/src/test/java/com/github/ambry/router/NonBlockingRouterTest.java