anchor.diff:  -export([find/2, find_all/1, find_query/2]).
   -export([create_record/2, update_record/3, delete_record/2]).
   -export([user_record/2]).
  -
  --define(CURRENT_USER_ID, <<"0">>).
   
   %%%===================================================================
   %%% data_backend_behaviour callbacks
  
positive.code: %%--------------------------------------------------------------------
  -spec find(ResourceType :: binary(), Id :: binary()) ->
      {ok, proplists:proplist()} | gui_error:error_result().
  find(<<"user">>, ?CURRENT_USER_ID) ->
      Auth = op_gui_utils:get_user_auth(),
      UserId = gui_session:get_user_id(),
      {ok, user_record(Auth, UserId)};
  find(<<"user">>, _) ->
      gui_error:unauthorized().
  
  
  %%--------------------------------------------------------------------
  
negative.code: -spec update_record(RsrcType :: binary(), Id :: binary(),
      Data :: proplists:proplist()) ->
      ok | gui_error:error_result().
  update_record(<<"user">>, UserId, Data) ->
      % FIXME: validate UserId
      case Data of
          [{<<"defaultSpaceId">>, DefaultSpace}] ->
              UserAuth = op_gui_utils:get_user_auth(),
  