code: def Open(self, hostname, port):
      
      server_url = 'http://{0:s}:{1:d}'.format(hostname, port)
  
      try:
        self._xmlrpc_proxy = xmlrpclib.ServerProxy(
            server_url, allow_none=True)
      except SocketServer.socket.error as exception:
        logger.warning((
            'Unable to connect to RPC server on {0:s}:{1:d} with error: '
            '{2!s}').format(hostname, port, exception))
        return False
  
      return True
docs: Opens a RPC communication channel to the server.
  
      Args:
        hostname (str): hostname or IP address to connect to for requests.
        port (int): port to connect to for requests.
  
      Returns:
        bool: True if the communication channel was established.