ServletContext servletContext = new MockServletContext();
scanner.init(servletContext);
// try to re-run the scan
scanner.scan();
Map<String, Set<String>> classMap = scanner.getClassIndex();
Assert.assertNotNull(classMap);
Assert.assertFalse(classMap.isEmpty());
Set<String> testBeanAnnotations = classMap.get(ScannerTestBean.class.getName());