@After
  public void cleanUp() throws IOException {
    if (Files.exists(accountBackupDir)) {
      Files.walk(accountBackupDir).map(Path::toFile).forEach(File::delete);
      Files.deleteIfExists(accountBackupDir);
    }
    assertFalse("Backup directory still exist", Files.exists(accountBackupDir));
  }
Delete all the backup files and backup directory.
@throws IOException if I/O error occurs
ambry-account/src/test/java/com/github/ambry/account/BackupFileManagerTest.java