    @Test
    public void testTransformUserCollection() {

        User mockUserOne = mock(User.class);
        User mockUserTwo = mock(User.class);

        List<User> userList = new ArrayList<>(5);
        userList.add(mockUserOne);
        userList.add(mockUserTwo);

        Collection<UserModel> userModelList = userModelDataMapper.transform(userList);

        assertThat(userModelList.toArray()[0], is(instanceOf(UserModel.class)));
        assertThat(userModelList.toArray()[1], is(instanceOf(UserModel.class)));
        assertThat(userModelList.size(), is(2));
    }