code: public void buildPackageHeader(XMLNode node, Content summariesTree) {
          String parsedPackageName = parsePackageName(currentPackage.name());
          if (! printedPackageHeaders.contains(parsedPackageName)) {
              writer.addPackageName(currentPackage,
                  parsePackageName(currentPackage.name()), summariesTree);
              printedPackageHeaders.add(parsedPackageName);
          }
      }
docs: Build the header for the given package.
  
  @param node the XML element that specifies which components to document
  @param summariesTree the tree to which the package header will be added