# File rss/trackback.rb, line 39
    def self.append_features(klass)
      super

      unless klass.class == Module
        %w(ping).each do |x|
          klass.install_have_child_element("#{TRACKBACK_PREFIX}_#{x}")
        end
        
        %w(about).each do |x|
          klass.install_have_children_element("#{TRACKBACK_PREFIX}_#{x}")
        end
      end
    end