boolean awaitBlobCreations() throws InterruptedException {
    return creationHelper.await(WAIT_SECONDS, TimeUnit.SECONDS);
  }
Waits for blob creations on all replicas
@return {@code true} if creations were received in all replicas.
@throws InterruptedException
ambry-test-utils/src/main/java/com/github/ambry/server/MockCluster.java