def get_predecessors(self, parametric_lane_id: str) -> list:
        """

        Args:
          parametric_lane_id: Id of ParametricLane for which to search predecessors.

        Returns:
          List of predecessors of a ParametricLane.
        """
        predecessors = []
        for successor_plane_id, successors in self._successors.items():
            if parametric_lane_id not in successors:
                continue

            if successor_plane_id in predecessors:
                continue

            predecessors.append(successor_plane_id)

        return predecessors


        Args:
          parametric_lane_id: Id of ParametricLane for which to search predecessors.

        Returns:
          List of predecessors of a ParametricLane.
        
metadrive/utils/opendrive/link_index.py