def blueprints(self) -> list[str]:
        """The registered names of the current blueprint upwards through
        parent blueprints.

        This will be an empty list if there is no current blueprint, or
        if URL matching failed.

        .. versionadded:: 2.0.1
        """
        name = self.blueprint

        if name is None:
            return []

        return _split_blueprint_path(name)
The registered names of the current blueprint upwards through
        parent blueprints.

        This will be an empty list if there is no current blueprint, or
        if URL matching failed.

        .. versionadded:: 2.0.1
        
src/flask/wrappers.py