private NonElement<TypeMirror, TypeElement> getXmlType(Reference r) {
if(r==null)
throw new IllegalArgumentException();
XmlJavaTypeAdapter xjta = r.annotations.getAnnotation(XmlJavaTypeAdapter.class);
XmlList xl = r.annotations.getAnnotation(XmlList.class);
Ref<TypeMirror, TypeElement> ref = new Ref<TypeMirror, TypeElement>(
reader,types.getNavigator(),r.type,xjta,xl);
return types.getTypeInfo(ref);