code: public void buildContents(XMLNode node, Content contentTree) {
          Content contentListTree = writer.getContentsHeader();
          printedPackageHeaders.clear();
          for (PackageElement pkg : configuration.packages) {
              if (hasConstantField(pkg) && !hasPrintedPackageIndex(pkg)) {
                  writer.addLinkToPackageContent(pkg, printedPackageHeaders, contentListTree);
              }
          }
          writer.addContentsList(contentTree, contentListTree);
      }
docs: Build the list of packages.
  
  @param node the XML element that specifies which components to document
  @param contentTree the content tree to which the content list will be added