code: @Override
  	protected void consume() {
  		E obj = null;
  		try {
  			obj = queue.take();
  		} catch (InterruptedException e) {
  			//thread.isInterrupted();
  			return;
  		}
  		process(obj);
  	}
docs: This method is overridden over parent class so that one piece of data is taken
  from the queue and {@link #process(Object)} is invoked.<br>
  这个方法被重载了，从而队列中的一份数据会被取出并调用{@link #process(Object)}方法。