@NbBundle.Messages({
   "ERR_mixedContentNotAllowed=Mixed content is not allowed in property elements"
 })
 private FxNode handlePropertyContent(CharSequence seq) {
   FxNode node = nodeStack.peek();
   if (!(node instanceof PropertySetter)) {
     addError("unexpected-characters", ERR_unexpectedCharacters());
     return null;
   }
   // if the property has already received some bean instances, report
   // invalid content
   PropertySetter ps = (PropertySetter) node;
   if (ps.getValues() != null) {
     addError("mixed-content-not-allowed", ERR_mixedContentNotAllowed());
   }
   accessor.addContent((PropertySetter) node, seq);
   return node;
 }