def _get_url(self, name: str) -> Optional[URL]:
    value = self._environ[name]
    if (value == '-'):
        return None
    else:
        return URL(value)
def _get_url(self, name: str) -> Optional[URL]:
    value = self._environ[name]
    if (value == '-'):
        return None
    else:
        return URL(value)