public class CategoriesServiceImplTest {


      @Mock
    CategoriesDao categoriesDao;

    @Before
    public void setup(){
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testGetCategories() throws Exception {
        CategoriesService categoriesService = new CategoriesServiceImpl();
        when(categoriesDao.getCategories()).thenReturn(null);
        Assert.assertNull(categoriesService.getCategories());

    }
}