@Test
public void testServiceClasses_emptyParamValueTag()
    throws IOException, SAXException, ParserConfigurationException, XPathExpressionException {

  WebXml webxml = new WebXmlBuilder()
      .raw(" <servlet>"
          + "   <servlet-name>SystemServiceServlet</servlet-name>"
          + "   <servlet-class>com.google.api.server.spi.SystemServiceServlet</servlet-class>"
          + "   <init-param>"
          + "     <param-name>services</param-name>"
          + "     <param-value/>"
          + "   </init-param>"
          + " </servlet>")
      .systemServiceServletMapping().build();
  List<String> serviceClasses = webxml.endpointsServiceClasses();
  Assert.assertEquals("Expecting nothing, found : " + serviceClasses, 0, serviceClasses.size());
}