code: @Handler
      public void onOutput(Output<ByteBuffer> event,
              TcpChannelImpl channel) throws InterruptedException {
          if (channels.contains(channel)) {
              channel.write(event);
          }
      }
docs: Writes the data passed in the event.
  
  The end of record flag is used to determine if a channel is
  eligible for purging. If the flag is set and all output has
  been processed, the channel is purgeable until input is
  received or another output event causes the state to be
  reevaluated.
  
  @param event the event
  @param channel the channel
  @throws InterruptedException the interrupted exception