private void validate(WebServiceFeature feature) {
// run validation
FeatureListValidatorAnnotation fva = feature.getClass().getAnnotation(FeatureListValidatorAnnotation.class);
if (fva != null) {
Class<? extends FeatureListValidator> beanClass = fva.bean();
try {
FeatureListValidator validator = beanClass.newInstance();
validator.validate(this);
} catch (InstantiationException e) {
throw new WebServiceException(e);