code: public void addConstantSummaries(Content contentTree, Content summariesTree) {
          if (configuration.allowTag(HtmlTag.SECTION) && summaryTree != null) {
              summariesTree.addContent(summaryTree);
          }
          if (configuration.allowTag(HtmlTag.MAIN)) {
              mainTree.addContent(summariesTree);
              contentTree.addContent(mainTree);
          } else {
              contentTree.addContent(summariesTree);
          }
      }
docs: {@inheritDoc}