anchor.diff:  
   %%--------------------------------------------------------------------
   %% A convenient abstraction of a Key-Value mapping data structure
  +%% specialized for the uses in this module
   %%--------------------------------------------------------------------
   
   -type map() :: dict().
  
positive.code: %% File processing.
  %%--------------------------------------------------------------------
  
  -spec get_all_files(args()) -> files().
  
  get_all_files(#args{files = Fs, files_r = Ds}) ->
    case filter_fd(Fs, Ds, fun test_erl_file_exclude_ann/1) of
  
negative.code: map__remove(Key, Dict) ->
    dict:erase(Key, Dict).
  
  -spec map__fold(fun((term(), term(), term()) -> map()), map(), map()) -> map().
  map__fold(Fun, Acc0, Dict) -> 
    dict:fold(Fun, Acc0, Dict).
  