Runnable runnable = new MessageDeliveryTask(message, id, timestamp);
TracingAwareExecutorService stage = StageManager.getStage(message.getMessageType());
assert stage != null : "No stage for message type " + message.verb;
stage.execute(runnable, state);
}
public void setCallbackForTests(int messageId, CallbackInfo callback)
{
callbacks.put(messageId, callback);