anchor.diff:  %%--------------------------------------------------------------------
   -spec save(datastore:document()) -> {ok, datastore:key()} | datastore:generic_error().
   save(Document) ->
  -    case datastore:save(?STORE_LEVEL, Document) of
  -        {ok, Uuid} ->
  -            catch file_meta:setup_onedata_user(provider, Uuid),
  -            {ok, Uuid};
  -        Error ->
  -            Error
  -    end.
  +    run_and_update_user(fun datastore:save/2, [?STORE_LEVEL, Document]).
   
   %%--------------------------------------------------------------------
   %% @doc
  
positive.code: %%--------------------------------------------------------------------
  -spec create(datastore:document()) -> {ok, datastore:key()} | datastore:create_error().
  create(Document) ->
      case datastore:create(?STORE_LEVEL, Document) of
          {ok, Uuid} ->
              catch file_meta:setup_onedata_user(provider, Uuid),
              {ok, Uuid};
          Error ->
              Error
      end.
  
  %%--------------------------------------------------------------------
  %% @doc
  
negative.code: -spec update(datastore:key(), Diff :: datastore:document_diff()) ->
      {ok, datastore:key()} | datastore:update_error().
  update(Key, Diff) ->
      run_and_update_user(fun datastore:update/4, [?STORE_LEVEL, ?MODULE, Key, Diff]).
  
  %%--------------------------------------------------------------------
  %% @doc
  