docs: public static void forEachURLSet (@Nonnull final Consumer <? super XMLSitemapURLSet> aConsumer)
    {
      ValueEnforcer.notNull (aConsumer, "Consumer");
      for (final IXMLSitemapProviderSPI aSPI : s_aProviders)
      {
        final XMLSitemapURLSet aURLSet = aSPI.createURLSet ();
        aConsumer.accept (aURLSet);
      }
    }