Return a clone of the current search request. Performs a shallow copy
        of all the underlying objects. Used internally by most state modifying
        APIs.

def _clone(self):
        """
        Return a clone of the current search request. Performs a shallow copy
        of all the underlying objects. Used internally by most state modifying
        APIs.
        """
        ubq = super(UpdateByQuery, self)._clone()

        ubq._response_class = self._response_class
        ubq._script = self._script.copy()
        ubq.query._proxied = self.query._proxied
        return ubq