code: protected void printElementWrapperTagStart(
          CmsObject cms,
          CmsContainerElementBean elementBean,
          CmsContainerPageBean page,
          boolean isGroupContainer)
      throws Exception {
  
          if (m_editableRequest) {
              StringBuffer result = new StringBuffer("<div class='");
              if (isGroupContainer) {
                  result.append(CmsContainerElement.CLASS_GROUP_CONTAINER_ELEMENT_MARKER);
              } else {
                  result.append(CmsContainerElement.CLASS_CONTAINER_ELEMENT_START_MARKER);
              }
              String serializedElement = getElementInfo(cms, elementBean, page);
              result.append("'");
              result.append(" " + CmsGwtConstants.ATTR_DATA_ELEMENT + "='").append(serializedElement);
              if (isGroupContainer) {
                  result.append("'>");
              } else {
                  result.append("' style='display:none;'></div>");
              }
              pageContext.getOut().print(result);
          }
      }
docs: Prints the opening element wrapper tag for the container page editor if we are in Offline mode.<p>
  
  @param cms the Cms context
  @param elementBean the element bean
  @param page the container page
  @param isGroupContainer true if the element is a group-container
  
  @throws Exception if something goes wrong