    @Test(expected = NullPointerException.class)
    //tests that the selectImageDown method always assigns a value to current image between 1 and 5
    public void selectImageDown() {


        for (int i = 0; i < 1000; i++) {
            mA.selectImageDown();
            assert MainActivity.sCurrentImage > -1 & MainActivity.sCurrentImage < 6;
        }
    }