BeanDescriptor bean = this.getConstraintsForClass(beanType);
PropertyDescriptor property = bean.getConstraintsForProperty(propertyName);
//get constraints for beanType.propertyName
Set<ConstraintDescriptor<?>> constraints = property.findConstraints().unorderedAndMatchingGroups(groups).getConstraintDescriptors();
//if no constraints are found using those groups, then we must take additional measures,
//namely checking to see if it is a group interface instead of a plain group (see JSR-303
//section 3.4.4. "Implicit Grouping")
if(constraints == null || constraints.isEmpty()) {