code: protected boolean postDatagram (PresentsConnection conn, Message msg)
          throws Exception
      {
          _flattener.reset();
  
          // flatten the message using the connection's sequencer
          DatagramSequencer sequencer = conn.getDatagramSequencer();
          sequencer.writeDatagram(msg);
  
          // if the message is too big, we must fall back to sending it through the stream channel
          if (_flattener.size() > Client.MAX_DATAGRAM_SIZE) {
              return false;
          }
  
          // note the actual transport
          msg.noteActualTransport(Transport.UNRELIABLE_UNORDERED);
  
          // extract as a byte array
          byte[] data = _flattener.toByteArray();
  
          // slap it on the queue
          _dataq.append(Tuple.newTuple(conn, data));
  
          return true;
      }
docs: Helper function for {@link #postMessage}; handles posting the message as a datagram.
  
  @return true if the datagram was successfully posted, false if it was too big.