code: private void setupConfig() {
  		if (config == null) {
  			if (tempFormBuilder == null) {
  				tempFormBuilder = new BasicFormBuilder();
  			}
  			if (tempProperties == null) {
  				tempProperties = new MinimalMessageSource();
  			}
  			config = new FormCheckerConfig(tempProperties, tempFormBuilder);
  		}
  	}
docs: set up the config-object for formchecker (handles absence of properties
  and formBuider)