code: @SuppressWarnings("serial") @Test public void testDeleteUsers() throws Exception {
    createUser("user1");
    users.createDefaultRoles();
    UserRequest request=new UserRequest("user1");
    request.setRoles(new HashSet<String>(){
  {
        add("user");
        add("admin");
      }
    }
  );
    controller.updateUsers(Collections.singleton(request));
    request=new UserRequest("user1");
    controller.deleteUsers(Collections.singleton(request));
    Set<UserResponse> responses=controller.getUsers(Collections.singleton(new UserRequest(null)));
    Assert.assertEquals(0,responses.size());
    RoleDAO roleDao=injector.getInstance(RoleDAO.class);
    RoleEntity re1=roleDao.findByName("user");
    RoleEntity re2=roleDao.findByName("admin");
    Assert.assertNotNull(re1);
    Assert.assertNotNull(re2);
  }
  