* on the containing target class of the method.
* @param invocation the current MethodInvocation
* @return the applicable validation groups as a Class array
*/
protected Class<?>[] determineValidationGroups(MethodInvocation invocation) {
Validated valid = AnnotationUtils.findAnnotation(invocation.getThis().getClass(), Validated.class);
return (valid != null ? valid.value() : new Class<?>[0]);
}