public static int shakeUp(String string, int upperLimit) {
        if (upperLimit < 1) {
            throw new IllegalArgumentException("upper limit must be greater than 0");
        }
        if (string == null) {
            return 0;
        }
        return (string.hashCode() & Integer.MAX_VALUE) % upperLimit;
    }
@Test
    void testShakeUpException() {
        assertThrows(IllegalArgumentException.class, () -> {
            UtilsAndCommons.shakeUp(null, 0);
        });
    }