docs: public void checkEmptyContainers() {
  
          if (getWidgetCount() == 0) {
              if (m_emptyContainerElement != null) {
                  m_emptyContainerElement.getStyle().clearDisplay();
              } else if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(m_containerData.getEmptyContainerContent())) {
                  // add empty container element
                  try {
                      m_emptyContainerElement = CmsDomUtil.createElement(m_containerData.getEmptyContainerContent());
                      getElement().appendChild(m_emptyContainerElement);
                  } catch (Exception e) {
                      CmsDebugLog.getInstance().printLine(e.getMessage());
                  }
              }
          } else if (m_emptyContainerElement != null) {
              m_emptyContainerElement.removeFromParent();
              m_emptyContainerElement = null;
          }
      }