docs: @Override
  	public Validator newValidator(String identifier) {
  		if (identifier==null) {
  			return null;
  		}
  		ValidatorFactory template;
  		synchronized (map) {
  			verifyMapIntegrity();
  			template = map.get(identifier);
  		}
  		if (template!=null) {
  			try {
  				return template.newValidator(identifier);
  			} catch (ValidatorFactoryException e) {
  				logger.log(Level.WARNING, "Failed to create validator.", e);
  				return null;
  			}
  		} else {
  			return null;
  		}
  	}