code: public Future<DeleteMessageResult> deleteMessage(DeleteMessageRequest request,
              AsyncHandler<DeleteMessageRequest, DeleteMessageResult> handler) {
          QueueBufferCallback<DeleteMessageRequest, DeleteMessageResult> callback = null;
          if (handler != null) {
              callback = new QueueBufferCallback<DeleteMessageRequest, DeleteMessageResult>(handler, request);
          }
  
          QueueBufferFuture<DeleteMessageRequest, DeleteMessageResult> future = sendBuffer.deleteMessage(request, callback);
          future.setBuffer(this);
          return future;
      }
docs: Asynchronously deletes a message from SQS.
  
  @return a Future object that will be notified when the operation is completed; never null