docs: def get_catalog_lookup_session(self):
          """Gets the catalog lookup session.
  
          return: (osid.cataloging.CatalogLookupSession) - a
                  ``CatalogLookupSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_catalog_lookup()`` is
                  ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_catalog_lookup()`` is ``true``.*
  
          """
          if not self.supports_catalog_lookup():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.CatalogLookupSession(runtime=self._runtime)