docs: private void initButtons() {
  
          m_addButton.addChoice(
              m_handler.getWidgetService(),
              new CmsChoiceMenuEntryBean(m_handler.getAttributeName()),
              new AsyncCallback<CmsChoiceMenuEntryBean>() {
  
                  public void onFailure(Throwable caught) {
  
                      // will not be called
  
                  }
  
                  public void onSuccess(CmsChoiceMenuEntryBean selectedEntry) {
  
                      // nothing to do
                  }
              });
          m_addButton.addDomHandler(new ClickHandler() {
  
              public void onClick(ClickEvent event) {
  
                  m_addButton.hide();
                  addNewAttributeValue();
                  event.preventDefault();
                  event.stopPropagation();
  
              }
          }, ClickEvent.getType());
  
          m_removeButton.setImageClass(I_CmsButton.CUT_SMALL);
          m_removeButton.setButtonStyle(ButtonStyle.FONT_ICON, null);
          m_removeButton.setHideFromTabNav(true);
  
          m_upButton.setImageClass(I_CmsButton.EDIT_UP_SMALL);
          m_upButton.setButtonStyle(ButtonStyle.FONT_ICON, null);
          m_upButton.setHideFromTabNav(true);
  
          m_downButton.setImageClass(I_CmsButton.EDIT_DOWN_SMALL);
          m_downButton.setButtonStyle(ButtonStyle.FONT_ICON, null);
          m_downButton.setHideFromTabNav(true);
  
          m_helpBubbleClose.setImageClass(I_CmsButton.DELETE_SMALL);
          m_helpBubbleClose.setButtonStyle(ButtonStyle.FONT_ICON, null);
          m_helpBubbleClose.setHideFromTabNav(true);
          if (CmsEditorBase.hasDictionary()) {
              m_addButton.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_VIEW_ADD_1, m_label));
              m_attributeChoice.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_CHOICE_ADD_CHOICE_1, m_label));
              m_removeButton.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_VIEW_DELETE_1, m_label));
              m_helpBubbleClose.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_VIEW_CLOSE_0));
              m_upButton.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_VIEW_MOVE_UP_0, m_label));
              m_downButton.setTitle(CmsEditorBase.getMessageForKey(CmsEditorBase.GUI_VIEW_MOVE_DOWN_0, m_label));
          }
      }