def _last_index(self, s):
        self.set_index(max(0, self._find_one_after_last_labeled_index() - 1))
def current_label_start(self):
        if self.current_label and self.message:
            return self.message.get_label_range(self.current_label, self.proto_view, False)[0]
        else:
            return -1