code: def call_sync(self, name, args, timeout=None):
          
          return self._blocking_request(self.call, timeout, name, args)
docs: Blocking version of :meth:`call`.
  
          :type    name: str
          :arg     name: Remote function name to call.
          :type    args: list
          :arg     args: Arguments passed to the remote function.
          :type timeout: int or None
          :arg  timeout: Timeout in second.  None means no timeout.
  
          If the called remote function raise an exception, this method
          raise an exception.  If you give `timeout`, this method may
          raise an `Empty` exception.