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

  WebXml webxml = new WebXmlBuilder()
      .servlet("SomeJunkServlet", "com.google.api.server.spi.SystemServiceServlet",
          "com.test.JunkEndpoint")
      .endpointsServlet("com.test.EndpointOne")
      .servletMapping("SomeJunkServlet", WebXmlBuilder.SPI_URL)
      .endpointsServletMapping()
      .build();
  List<String> serviceClasses = webxml.endpointsServiceClasses();
  Assert.assertEquals(1, serviceClasses.size());
  Assert.assertEquals(serviceClasses.get(0), "com.test.JunkEndpoint");
}