code: def _download_metadata_archive(self):
          
          with tempfile.NamedTemporaryFile(delete=False) as metadata_archive:
              shutil.copyfileobj(urlopen(self.catalog_source), metadata_archive)
          yield metadata_archive.name
          remove(metadata_archive.name)
docs: Makes a remote call to the Project Gutenberg servers and downloads
          the entire Project Gutenberg meta-data catalog. The catalog describes
          the texts on Project Gutenberg in RDF. The function returns a
          file-pointer to the catalog.