class RandomIdNoLuhnProvider implements SessionIdProvider {

  @Override
  public String readId(String value) {
    if (value == null) {
      return null;
    }
    String trimmedValue = value.trim();
    if (trimmedValue.isEmpty()) {
      return null;
    }
    if (trimmedValue.length() != getLengthInCharacters()) {
      return null;
    }
    return trimmedValue;
  }

  public  RandomIdNoLuhnProvider();
    RandomIdNoLuhnProvider(int length);

}