private void isCorrect() {
        File file = new File(dataBaseDirectory);
        if (file.isFile()) {
            throw new MultiDataBaseException(dataBaseDirectory + " isn't directory!");
        }

        String[] dirs = file.list();
        checkNames(dirs, "dir");
        for (int i = 0; i < dirs.length; ++i) {
            if (!dirs[i].equals("signature.tsv")) {
                isCorrectDirectory(dataBaseDirectory + File.separator + dirs[i]);
            }
        }
    }