@Test
public void testService() {

    CommonClassDao dao = Mockito.mock(CommonClassDao.class);
    List<Object> value = new ArrayList<Object>();
    when(dao.getData(PolicyVersion.class)).thenReturn(value);
    MetricService service = new MetricService(dao);
    assertNotNull(service);
    MockHttpServletResponse response = new MockHttpServletResponse();
    MetricService.doGetPolicyMetrics(response);
    assertEquals(HttpServletResponse.SC_BAD_REQUEST, response.getStatusCode());
}