def weight_id(self, val: str) -> None:
        """
        Set weight id for the const.
        """
        assert isinstance(val, str), f"weight_id must be type of str. Got {type(val)}."
        assert self._weight_id is None, f"cannot set {self.name} weight_id twice."
        self._weight_id = val

        Set weight id for the const.
        
coremltools/converters/mil/mil/ops/defs/iOS15/control_flow.py