code: void checkWriteSuspend(ChannelHandlerContext ctx, long delay, long queueSize) {
          if (queueSize > maxWriteSize || delay > maxWriteDelay) {
              setUserDefinedWritability(ctx, false);
          }
      }
docs: Check the writability according to delay and size for the channel.
  Set if necessary setUserDefinedWritability status.
  @param delay the computed delay
  @param queueSize the current queueSize