anchor.diff:    Key = lists:nth(rand:uniform(length(Keys)), Keys),
     [#song{movie_id = MovieId}] = mnesia:dirty_read({song, Key}),
     {ok, MovieId}.
  +
  +get_songs_count() ->
  +  length(mnesia:dirty_all_keys(song)).
   
   handle_info(start_expiring_timer, RecentMovies) ->
     spawn_gc(),
  
positive.code:               end,
    expire_items(Tail, NewResult).
  
  calculate_ttl(ItemsCount) when is_integer(ItemsCount) ->
    ItemsCount * 120 * 1000.
  
  get_random_movie() ->
    error_logger:info_msg("mnesia:get_random_movie"),
  
negative.code: 
  handle_call({get_random}, _From, RecentMovies) ->
    RandomMovieId = randomize(RecentMovies),
    NewState = lists:append([{RandomMovieId, calculate_ttl()}], RecentMovies),
    {reply, {ok, RandomMovieId}, NewState}.
  
  randomize(RecentMovies) ->
  