code: protected void initialize(final IModel<T> _model,
                                final EFapsContentReference _reference,
                                final String _label)
      {
          final ButtonLink<T> link;
          if (_model == null) {
              link = new ButtonLink<>("button");
          } else {
              link = new ButtonLink<>("button", _model);
          }
          add(link);
          link.add(new ButtonImage("icon", _reference));
          link.add(new Label("label", _label == null ? "" : _label));
      }
docs: Init the component.
  @param _model        Model for this component
  @param _reference    refernce to an icon
  @param _label        label of the button