code: public static <T> CheckGroup<T> newCheckGroup(final String id,
  		final IModel<? extends Collection<T>> model)
  	{
  		final CheckGroup<T> checkGroup = new CheckGroup<>(id, model);
  		checkGroup.setOutputMarkupId(true);
  		return checkGroup;
  	}
docs: Factory method for create a new {@link CheckGroup}.
  
  @param <T>
  the generic type of the model
  @param id
  the id
  @param model
  the model
  @return the new {@link CheckGroup}