code: async def _download_predicate_data(self, class_, controller):
          
          await self.authenticate()
  
          url = ('{0}{1}/modeldef/class/{2}'
                 .format(self.base_url, controller, class_))
  
          resp = await self._ratelimited_get(url)
  
          await _raise_for_status(resp)
  
          resp_json = await resp.json()
          return resp_json['data']
docs: Get raw predicate information for given request class, and cache for
          subsequent calls.