code: @Override
      public ExtraJaxbClassesModel getExtraJaxbClasses() {
          if (_extraJaxbClasses == null) {
              _extraJaxbClasses = (ExtraJaxbClassesModel)getFirstChildModel(EXTRA_JAXB_CLASSES);
          }
          return _extraJaxbClasses;
      }
docs: {@inheritDoc}