code: def _Open(self, hostname, port):
      
      try:
        self._xmlrpc_server = SimpleXMLRPCServer.SimpleXMLRPCServer(
            (hostname, port), logRequests=False, allow_none=True)
      except SocketServer.socket.error as exception:
        logger.warning((
            'Unable to bind a RPC server on {0:s}:{1:d} with error: '
            '{2!s}').format(hostname, port, exception))
        return False
  
      self._xmlrpc_server.register_function(
          self._callback, self._RPC_FUNCTION_NAME)
      return True
docs: Opens the RPC communication channel for clients.
  
      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 successfully opened.