langchain/document_loaders/blackboard.py/BlackboardLoader/parse_filename
class BlackboardLoader:    def parse_filename(self, url: str) -> str:
        """Parse the filename from a url.

        Args:
            url: Url to parse the filename from.

        Returns:
            The filename.
        """
        if (url_path := Path(url)) and url_path.suffix == ".pdf":
            return url_path.name
        else:
            return self._parse_filename_from_url(url)