def _add_metadata(
        self,
        op: onnx.ModelProto,  # type:ignore
        additional_metadata: Optional[list[tuple[str, str]]] = None,
    ) -> onnx.ModelProto:  # type:ignore
        """Add metadata to the combined ONNX model.

        Args:
            op: onnx operation.
            additional_metadata:
                A list of tuples representing additional metadata to add to the combined ONNX model.
                Example: [("version", 0.1)], [("date", 20240909)].

        """
        op = kornia.onnx.utils.add_metadata(op, additional_metadata)
        return op
Add metadata to the combined ONNX model.

        Args:
            op: onnx operation.
            additional_metadata:
                A list of tuples representing additional metadata to add to the combined ONNX model.
                Example: [("version", 0.1)], [("date", 20240909)].

        
kornia/core/mixin/onnx.py