anchor.diff:  prefetch_data_fun(FileUuid, #file_block{offset = O, size = S}) ->
       fun() ->
           try
  -            ?info("PREFETCH ~p ~p", [FileUuid, #file_block{offset = O + S, size = ?PREFETCH_SIZE - S}]),
               replica_synchronizer:synchronize(FileUuid, #file_block{offset = O + S, size = ?PREFETCH_SIZE - S}, false)
           catch
               _:Error ->
  
positive.code: on_complete_fun() ->
      Self = self(),
      fun(Ref, Status) ->
          ?info("COMPLETE ~p, ~p", [Ref, Status]),
          Self ! {Ref, Status}
      end.
  
  
negative.code: %%--------------------------------------------------------------------
  -spec notify_fun(any(), any(), any()) -> ok.
  notify_fun(Ref, Offset, Size) ->
      ok.
  
  %%--------------------------------------------------------------------
  %% @doc
  