code: public void send( String dest, String mesg, Map header ) {
      if (header == null) header = new HashMap();
      header.put( "destination", dest );
      transmit( Command.SEND, header, mesg );
    }
docs: Send a message to a channel.
  
  @param dest The name of the channel to send the message to
  @param mesg The message to send.
  @param header Additional headers to send to the server.