code: def get_resources(self, collections):
          
          res_map = self.request.registry._model_collections
          resources = [res for res in res_map.values()
                       if res.collection_name in collections]
          resources = [res for res in resources if res]
          return set(resources)
docs: Get resources that correspond to values from :collections:.
  
          :param collections: Collection names for which resources should be
              gathered
          :type collections: list of str
          :return: Gathered resources
          :rtype: list of Resource instances