public static boolean equalsIgnoreCase(String a, String b) {
        if (a == null) {
            return b == null;
        }
        return a.equalsIgnoreCase(b);
    }
@Test
    void testEqualsIgnoreCase() {
        Assertions.assertTrue(StringUtils.equalsIgnoreCase("a", "a"));
        Assertions.assertTrue(StringUtils.equalsIgnoreCase("a", "A"));
        Assertions.assertTrue(StringUtils.equalsIgnoreCase("A", "a"));
        Assertions.assertFalse(StringUtils.equalsIgnoreCase("1", "2"));
        Assertions.assertFalse(StringUtils.equalsIgnoreCase(null, "1"));
        Assertions.assertFalse(StringUtils.equalsIgnoreCase("1", null));
        Assertions.assertFalse(StringUtils.equalsIgnoreCase("", null));
        Assertions.assertFalse(StringUtils.equalsIgnoreCase(null, ""));
    }