code: protected String escapeXmlSpecialCharacters(String url) {
  		// https://stackoverflow.com/questions/1091945/what-characters-do-i-need-to-escape-in-xml-documents
  		return url
  				.replace("&", "&amp;") // must be escaped first!!!
  				.replace("\"", "&quot;")
  				.replace("'", "&apos;")
  				.replace("<", "&lt;")
  				.replace(">", "&gt;");
  	}
docs: Escape special characters in XML
  @param url Url to be escaped
  @return Escaped url