List<? extends Property> propList = mapping.getWrapperStyleDrilldown();
for (Property pro : propList) {
if (pro.elementName().getNamespaceURI().equals(item.getNamespaceURI())
&& pro.elementName().getLocalPart().equals(item.getLocalPart())) {
JType type = pro.type();
if (type instanceof JDefinedClass
&& ((JDefinedClass)type).isAbstract()) {
//no default values for abstract classes
return null;
}