anchor.diff:  for(N, F) ->
       F(),
       for(N - 1, F).
  +
  +
  +-spec fill_file_with_dummy_data(node(), session:id(), file_id:file_guid()) -> ok.
  +fill_file_with_dummy_data(Node, SessId, Guid) ->
  +    {ok, FileHandle} = ?assertMatch(
  +        {ok, _},
  +        lfm_proxy:open(Node, SessId, {guid, Guid}, write)
  +    ),
  +    ?assertMatch({ok, 4}, lfm_proxy:write(Node, FileHandle, 0, <<"DATA">>)),
  +    ?assertMatch(ok, lfm_proxy:fsync(Node, FileHandle)),
  +    ?assertMatch(ok, lfm_proxy:close(Node, FileHandle)).
  
positive.code:         root_dir = atom_to_binary(?FUNCTION_NAME, utf8),
          files = [#file{
              name = <<"file1">>,
              perms = [?read_object, ?write_object]
          }],
          operation = fun(_OwnerSessId, SessId, TestCaseRootDirPath, ExtraData) ->
              FilePath = <<TestCaseRootDirPath/binary, "/file1">>,
  
negative.code:         rm_dir_test,
  
          create_file_test,
          open_for_read_test,
          open_for_write_test,
          open_for_rdwr_test,
          create_and_open_test,
          truncate_test,
          mv_file_test,
  