docs: def get_item_lookup_session(self):
          """Gets the ``OsidSession`` associated with the item lookup service.
  
          return: (osid.assessment.ItemLookupSession) - an
                  ``ItemLookupSession``
          raise:  OperationFailed - unable to complete request
          raise:  Unimplemented - ``supports_item_lookup()`` is ``false``
          *compliance: optional -- This method must be implemented if
          ``supports_item_lookup()`` is ``true``.*
  
          """
          if not self.supports_item_lookup():
              raise errors.Unimplemented()
          # pylint: disable=no-member
          return sessions.ItemLookupSession(runtime=self._runtime)