anchor.diff:  
               Ans = case file_location:save(DocToSave) of
                   {ok, _} ->
  -                    flush_local_blocks(Key, DelBlocks, AddBlocks, Type);
  +                    flush_local_blocks(DocToSave, DelBlocks, AddBlocks, Type);
                   Error ->
                       ?error("Flush failed for key ~p: ~p", [Key, Error]),
                       Error
  
positive.code: %% Flushes local blocks.
  %% @end
  %%-------------------------------------------------------------------
  -spec flush_local_blocks(file_location:id(), list(), list(), flush_type()) ->
      ok | {error, term()} | [{error, term()}].
  flush_local_blocks(Key, DelBlocks, AddBlocks, Type) ->
      Proceed = case ?LOCAL_BLOCKS_FLUSH of
          always -> true;
          on_terminate -> Type =:= terminate
  
negative.code:                     verify_flush_ans(Key, Check1, Check2)
              end;
          {true, doc} ->
              case file_local_blocks:update(Key, get_blocks(Key) -- PublicBlocks) of
                  ok ->
                      erase({?DELETED_BLOCKS, Key}),
                      erase({?RESET_BLOCKS, Key}),
  