anchor.diff:  %% exported functions
   -export([make/0,
            torrents/0,
  -         copy_file/1,
  +         copy_torrent/1,
            copy_path/1,
            info_path/1,
            info_hash/1,
  
positive.code: %% The torrent file is copied to $DOTDIR/$INFOHASH.torrent. After a copy
  %% of the torrent file has been made it is safe to delete the original file.
  %% @end
  -spec copy_file(Torrentfile::string()) -> ok.
  copy_file(Torrentfile) when is_list(Torrentfile) ->
      case info_hash(Torrentfile) of
          {error, _}=Error ->
              Error;
  
negative.code:     ?assertEqual({ok, testhex()}, ?MODULE:hex_info_hash(testhash())).
  
  test_copy_torrent() ->
      ?assertEqual({ok, testhex()}, ?MODULE:copy_torrent(testpath())),
      ?assertEqual({ok, [testhex()]}, ?MODULE:torrents()).
  
  test_info_filename() ->
      {ok, Infohash} = ?MODULE:copy_torrent(testpath()),
      ?assertEqual(testinfo(), lists:last(filename:split(?MODULE:info_path(Infohash)))).
  
  test_info_hash() ->
  