@Test
public void thatCanApplyContrastEffect() {

    assertThat(HaloCloudinary.Effects.contrast(10).toString().equals("e_contrast:10")).isTrue();
    assertThat(HaloCloudinary.Effects.contrast(null).toString().equals("e_contrast")).isTrue();
    assertThat(HaloCloudinary.Effects.contrast(-1000).toString().equals("e_contrast")).isTrue();
}