code: @Override
  	public String[] toStringArray() {
  		ArrayList<String> out = new ArrayList<>();
  		out.add("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n");
  		out.add("<sitemapindex xmlns=\"http://www.sitemaps.org/schemas/sitemap/0.9\">\n");
  		ArrayList<WebPage> values = new ArrayList<>(urls.values());
  		Collections.sort(values);
  		for (WebPage webPage : values) {
  			out.add(constructUrl(webPage));
  		}
  		out.add("</sitemapindex>");
  		return out.toArray(new String[] {});
  	}
docs: Construct sitemap to String array
  @return String array