nodes: 0, module; 1, function_definition; 2, function_name:photos; 3, parameters; 4, block; 5, identifier:self; 6, identifier:username; 7, default_parameter; 8, default_parameter; 9, default_parameter; 10, expression_statement; 11, expression_statement; 12, expression_statement; 13, return_statement; 14, identifier:page; 15, integer:1; 16, identifier:per_page; 17, integer:10; 18, identifier:order_by; 19, string:"latest"; 20, comment:"""
          Get a list of photos uploaded by a user.
  
          :param username [string]: The user’s username. Required.
          :param page [integer]: Page number to retrieve. (Optional; default: 1)
          :param per_page [integer]: Number of items per page. (Optional; default: 10)
          :param order_by [string]: How to sort the photos. Optional.
          (Valid values: latest, oldest, popular; default: latest)
          :return: [Array]: A single page of the Photo list.
          """; 21, assignment; 22, assignment; 23, call; 24, identifier:url; 25, call; 26, identifier:result; 27, call; 28, attribute; 29, argument_list; 30, attribute; 31, argument_list; 32, attribute; 33, argument_list; 34, identifier:PhotoModel; 35, identifier:parse_list; 36, identifier:result; 37, string:"/users/{username}/photos"; 38, identifier:format; 39, keyword_argument; 40, identifier:self; 41, identifier:_photos; 42, identifier:url; 43, identifier:username; 44, keyword_argument; 45, keyword_argument; 46, keyword_argument; 47, identifier:username; 48, identifier:username; 49, identifier:page; 50, identifier:page; 51, identifier:per_page; 52, identifier:per_page; 53, identifier:order_by; 54, identifier:order_by
code: def photos(self, username, page=1, per_page=10, order_by="latest"):
          """
          Get a list of photos uploaded by a user.
  
          :param username [string]: The user’s username. Required.
          :param page [integer]: Page number to retrieve. (Optional; default: 1)
          :param per_page [integer]: Number of items per page. (Optional; default: 10)
          :param order_by [string]: How to sort the photos. Optional.
          (Valid values: latest, oldest, popular; default: latest)
          :return: [Array]: A single page of the Photo list.
          """
          url = "/users/{username}/photos".format(username=username)
          result = self._photos(url, username, page=page, per_page=per_page, order_by=order_by)
          return PhotoModel.parse_list(result)