code: def all(self, page=1, per_page=10):
          
          url = "/collections"
          result = self._all(url, page=page, per_page=per_page)
          return CollectionModel.parse_list(result)
docs: Get a single page from the list of all collections.
  
          :param page [integer]: Page number to retrieve. (Optional; default: 1)
          :param per_page [integer]: Number of items per page. (Optional; default: 10)
          :return: [Array]: A single page of the Collection list.