def METHOD_NAME(self, tmp_path):
    # Set up expired ERFA leap seconds.
    expired = self.erfa_ls[self.erfa_ls["year"] < 2017]
    expired.update_erfa_leap_seconds(initialize_erfa="empty")
    # Create similarly expired file.
    expired_file = str(tmp_path / "expired.dat")
    with open(expired_file, "w") as fh:
        fh.write(
            "\n".join(
                ["# File expires on 28 June 2010"] + [str(item) for item in expired]
            )
        )
    with pytest.warns(iers.IERSStaleWarning):
        update_leap_seconds(["erfa", expired_file])