code: private void initTypeCombo(WidgetType defaultType) {
  
          IndexedContainer container = new IndexedContainer();
  
          container.addContainerProperty("caption", String.class, "");
  
          Item item = container.addItem(WidgetType.groupwidget);
          item.getItemProperty("caption").setValue(CmsVaadinUtils.getMessageText(Messages.GUI_USERMANAGEMENT_GROUP_0));
  
          item = container.addItem(WidgetType.userwidget);
          item.getItemProperty("caption").setValue(CmsVaadinUtils.getMessageText(Messages.GUI_USERMANAGEMENT_USER_0));
  
          m_typeCombo.setContainerDataSource(container);
          m_typeCombo.select(defaultType);
          m_typeCombo.setEnabled(m_type.equals(WidgetType.principalwidget) | (m_type == null));
          m_typeCombo.setItemCaptionPropertyId("caption");
          m_typeCombo.setNullSelectionAllowed(false);
          m_typeCombo.setNewItemsAllowed(false);
  
      }
docs: Init ComboBox for choosing type of principal.<p>
  @param defaultType Default mode to open