code: def is_assignee(self, login):
          
          if not login:
              return False
          url = self._build_url('assignees', login, base_url=self._api)
          return self._boolean(self._get(url), 204, 404)
docs: Check if the user is a possible assignee for an issue on this
          repository.
  
          :returns: :class:`bool`