docs: public void addWithLeftMargin(E tabContent, String tabName) {
  
          tabContent.addStyleName(I_CmsLayoutBundle.INSTANCE.generalCss().cornerAll());
          m_tabPanel.add(tabContent, CmsDomUtil.stripHtml(tabName));
  
          int tabIndex = m_tabPanel.getWidgetIndex(tabContent);
          Element tabElement = getTabElement(tabIndex);
          if (tabElement != null) {
              tabElement.addClassName(I_CmsLayoutBundle.INSTANCE.tabbedPanelCss().tabLeftMargin());
              if (!m_panelStyle.equals(CmsTabbedPanelStyle.classicTabs)) {
                  tabElement.addClassName(I_CmsLayoutBundle.INSTANCE.generalCss().buttonCornerAll());
                  tabElement.addClassName(I_CmsLayoutBundle.INSTANCE.tabbedPanelCss().borderAll());
              }
          }
          m_tabPanel.checkTabOverflow();
      }