def _set_depth(self) -> None:
        """
        Sets operator depth and dst_ops.
        This function must be called by each operator subclass inside
        __call__() method once self._attrs["inputs"] is set.
        """
        max_depth = 0
        if self._attrs["inputs"] is not None:
            for inp in self._attrs["inputs"]:
                max_depth = max(max_depth, inp._attrs["depth"])
                inp._attrs["dst_ops"].add(self)
        self._attrs["depth"] = max_depth

        Sets operator depth and dst_ops.
        This function must be called by each operator subclass inside
        __call__() method once self._attrs["inputs"] is set.
        
python/aitemplate/compiler/base.py