code: public void setIcon(String iconClasses, String detailIconClasses) {
  
          m_iconPanel.setVisible(true);
          HTML iconWidget = new HTML();
          m_iconPanel.setWidget(iconWidget);
          iconWidget.setStyleName(iconClasses + " " + m_fixedIconClasses);
          // render the detail icon as an overlay above the main icon, if required
          if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(detailIconClasses)) {
              iconWidget.setHTML(
                  "<span class=\""
                      + detailIconClasses
                      + " "
                      + I_CmsLayoutBundle.INSTANCE.listItemWidgetCss().pageDetailType()
                      + "\"></span>");
          }
      }
docs: Sets the icon for this item using the given CSS classes.<p>
  
  @param iconClasses the CSS classes
  @param detailIconClasses the detail type icon classes if available