def to_header(self) -> str:
        """Convert the etags set into a HTTP header string."""
        if self.star_tag:
            return "*"
        return ", ".join(
            [f'"{x}"' for x in self._strong] + [f'W/"{x}"' for x in self._weak]
        )
Convert the etags set into a HTTP header string.
src/werkzeug/datastructures/etag.py