code: public Content getSerializedContent(Content serializedTreeContent) {
          HtmlTree divContent = HtmlTree.DIV(HtmlStyle.serializedFormContainer,
                  serializedTreeContent);
          if (configuration.allowTag(HtmlTag.MAIN)) {
              mainTree.addContent(divContent);
              return mainTree;
          } else {
              return divContent;
          }
      }
docs: Get the serialized content tree section.
  
  @param serializedTreeContent the serialized content tree to be added
  @return a div content tree