@Override
 public void populateItem(
     Item<ICellPopulator<T>> cellItem, String componentId, IModel<T> rowModel) {
   cellItem.add(factory.createPropertyComponent(componentId, rowModel, propertyName, context));
 }
 @Override
 public Component getHeader(String componentId) {
   return factory.createPropertyLabel(componentId, propertyName);
 }