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