Cancel an ongoing confirmed commit. Depends on the `:candidate` and `:confirmed-commit` capabilities.

        *persist-id* value must be equal to the value given in the <persist> parameter to the previous <commit> operation.

def request(self, persist_id=None):
        """Cancel an ongoing confirmed commit. Depends on the `:candidate` and `:confirmed-commit` capabilities.

        *persist-id* value must be equal to the value given in the <persist> parameter to the previous <commit> operation.
        """
        node = new_ele("cancel-commit")
        if persist_id is not None:
            sub_ele(node, "persist-id").text = persist_id

        return self._request(node)