code: public void addButton(Widget button, int position) {
  
          m_buttonPanel.insert(button, position);
          m_buttonPanel.setStyleName(I_CmsLayoutBundle.INSTANCE.dialogCss().popupButtonPanel());
      }
docs: Adds a button widget to the button panel before the given position.<p>
  
  @param button the button widget
  @param position the position to insert the button