### Question:
AngleMath { public static double difference(final double angle1, final double angle2) { return normalizeAngle(angle1 - angle2); } private  AngleMath(); static double normalizeAngle(final double angle); static double difference(final double angle1, final double angle2); static double cos(final double number); static double sin(final double number); static double tan(final double number); static double deg2rad(final double deg); static double rad2deg(final double rad); static double mirror(final double angle); static final double PI; static final double PI_TWO; static final double PI_HALF; static final double PI_QUART; static final double DEG_180_IN_RAD; static final double DEG_090_IN_RAD; static final double DEG_045_IN_RAD; }### Answer:
@Test public void testDifference() { assertThat(AngleMath.difference(1, 2)).isEqualTo(-1.0); assertThat(AngleMath.difference(2, 1)).isEqualTo(1.0); assertThat(AngleMath.difference(50, 10)).isEqualTo(AngleMath.normalizeAngle(40)); assertThat(AngleMath.difference(50, 48)).isEqualTo(2.0); assertThat(AngleMath.difference(50, 90)).isEqualTo(AngleMath.normalizeAngle(-40)); assertThat(AngleMath.difference(0, 0)).isEqualTo(0.0); assertThat(AngleMath.difference(50, 10)).isEqualTo(AngleMath.normalizeAngle(40)); }