anchor.diff:      {[], [], State},
       Dbs
     ),
  -  
  +
     case Dbs -- Dbs2 of
       [] -> {Loaded, State2};
       NDbs ->
  
positive.code:     undefined ->
        {Reply, NState} = do_create_db(Config, State),
        {reply, Reply, NState};
      [_Db] ->
        {reply, {error, db_exists}, State}
    end;
  
  
negative.code:   Path = filename:join(data_dir(), "barrel_config"),
    ok = filelib:ensure_dir(Path),
    Path.
  
  persist_config(Conf) ->
    file:write_file(conf_path(), jsx:encode(Conf)).
  
  