anchor.diff:          {ok, #file_attr{guid = Guid}} ->
               {ok, ObjectId} = file_id:guid_to_objectid(Guid),
               {ok, [#{<<"id">> => ObjectId, <<"path">> => Path}]};
  -        Error ->
  -            Error
  +        {error, Errno} ->
  +            ?ERROR_POSIX(Errno)
      end;
   
   get(#op_req{client = Cl, data = Data, gri = #gri{id = FileGuid, aspect = attrs}}, _) ->
  -    SessionId = Cl#client.id,
  +    SessionId = Cl#client.session_id,
       Attributes = case maps:get(<<"attribute">>, Data, undefined) of
           undefined -> ?ALL_BASIC_ATTRIBUTES;
           Attr -> [Attr]
  
positive.code: %%--------------------------------------------------------------------
  -spec get(op_logic:req(), op_logic:entity()) -> op_logic:get_result().
  get(#op_req{client = Cl, data = Data, gri = #gri{id = FileGuid, aspect = list}}, _) ->
      SessionId = Cl#client.id,
      Limit = maps:get(<<"limit">>, Data, ?DEFAULT_LIST_ENTRIES),
      Offset = maps:get(<<"offset">>, Data, ?DEFAULT_LIST_OFFSET),
  
      {ok, Path} = logical_file_manager:get_file_path(SessionId, FileGuid),
  
      case logical_file_manager:stat(SessionId, {guid, FileGuid}) of
          {ok, #file_attr{type = ?DIRECTORY_TYPE, guid = Guid}} ->
              {ok, Children} = logical_file_manager:ls(SessionId, {guid, FileGuid}, Offset, Limit),
              {ok, lists:map(fun({ChildGuid, ChildPath}) ->
                      {ok, ObjectId} = file_id:guid_to_objectid(ChildGuid),
                      #{<<"id">> => ObjectId, <<"path">> => filename:join(Path, ChildPath)}
  
negative.code:     ?ERROR_NOT_SUPPORTED.
  
  
  %%%===================================================================
  %%% Internal functions
  %%%===================================================================
  
  
  -spec extract_lfm_res({ok, term()} | {error, term()}) ->
      {ok, term()} | no_return().
  extract_lfm_res({ok, _} = Res) -> Res;
  extract_lfm_res({error, Errno}) -> throw(?ERROR_POSIX(Errno)).
  
  
  %%--------------------------------------------------------------------
  