anchor.diff:      Result :: term().
   %% ====================================================================
   save_new_file_descriptor(ProtocolVersion, Uuid, FuseID, Validity) ->
  -    ct:print("save_new_file_descriptor/4(~p,~p,~p): ~p",[ProtocolVersion, Uuid, FuseID, Validity, process_info(self(), backtrace)]),
  +    ct:print("save_new_file_descriptor/4(~p,~p,~p, ~p): ~p",[ProtocolVersion, Uuid, FuseID, Validity, process_info(self(), last_calls)]),
       Descriptor = update_file_descriptor(#file_descriptor{file = Uuid, fuse_id = FuseID}, Validity),
       case dao_lib:apply(dao_vfs, save_descriptor, [Descriptor], ProtocolVersion) of
           {error, Reason} ->
  
positive.code:     Result :: term().
  %% ====================================================================
  save_file_descriptor(ProtocolVersion, File, Validity) ->
      ct:print("save_file_descriptor/3(~p,~p,~p): ~p",[ProtocolVersion, File, Validity, process_info(self(), backtrace)]),
      Descriptor = update_file_descriptor(File#db_document.record, Validity),
      case dao_lib:apply(dao_vfs, save_descriptor, [File#db_document{record = Descriptor}], ProtocolVersion) of
          {error, Reason} ->
  
negative.code:     Result :: term().
  %% ====================================================================
  save_file_descriptor(ProtocolVersion, Uuid, FuseID, Validity) ->
      ct:print("save_file_descriptor/4(~p,~p,~p, ~p): ~p",[ProtocolVersion, Uuid, FuseID, Validity, process_info(self(), last_calls)]),
      case FuseID of
          ?CLUSTER_FUSE_ID -> {ok, ok};
          _ ->
  