code: public void setPort( int port )
      {
          assert ( port >= 0 && port <= 65535 ) || ( port == UNDEFINED_PORT )
                   : "Invalid port" ;
  
          if ( ( port > 65535 ) || ( port < 0 && port != UNDEFINED_PORT ) )
          {
               throw new IllegalArgumentException( "A port must be between 0 and 65535 or equal to "
                                                   + UNDEFINED_PORT + ".");
          }
  
          _port = port;
      }
docs: Sets the port.
  
  @param port port