/**
     * Tests the {@link PacUnicodeString#check(String)} method with null string and non-zero pointer.
     * This should throw an exception as it's an invalid state.
     */
    @Test
    void testCheck_withNullStringAndNonZeroPointer() {
        // Non-zero pointer should have a corresponding string
        PacUnicodeString pacString = new PacUnicodeString((short) 10, (short) 20, 100);
        String testString = null;