code: public boolean send(PooledByteBuffer pooled) throws IOException {
          if(isWritesShutdown()) {
              throw UndertowMessages.MESSAGES.channelIsClosed();
          }
          boolean result = sendInternal(pooled);
          if(result) {
              flush();
          }
          return result;
      }
docs: Send a buffer to this channel.
  
  @param pooled Pooled ByteBuffer to send. The buffer should have data available. This channel will free the buffer
  after sending data
  @return true if the buffer was accepted; false if the channel needs to first be flushed
  @throws IOException if this channel is closed