code: def r_collections(self, lang=None):
          
          collection = self.resolver.getMetadata()
          return {
              "template": "main::collection.html",
              "current_label": collection.get_label(lang),
              "collections": {
                  "members": self.make_members(collection, lang=lang)
              }
          }
docs: Retrieve the top collections of the inventory
  
          :param lang: Lang in which to express main data
          :type lang: str
          :return: Collections information and template
          :rtype: {str: Any}