@Override
 public void applyAssociationOverride(Map<String, AssociationOverride> associationOverrideMap) {
   if (elementSource != null && elementSource instanceof AnnotationAttributeSource) {
     ((AnnotationAttributeSource) elementSource).applyAssociationOverride(associationOverrideMap);
   } else {
     // TODO what to do here, store this and apply later ( to the owner side )?
   }
 }
 @Override
 public void applyAttributeOverride(Map<String, AttributeOverride> attributeOverrideMap) {
   if (elementSource != null && elementSource instanceof AnnotationAttributeSource) {
     ((AnnotationAttributeSource) elementSource).applyAttributeOverride(attributeOverrideMap);
   }
 }