### Question:
Utils { public static boolean isIpAddress(String ip) { if (ip == null || ip.isEmpty()) { return false; } if (ip.indexOf(':') > 0 && ip.split(":").length == 8) { return true; } String[] parts = ip.split("\\."); if (parts.length != 4) { return false; } for (String part : parts) { Value<Integer> ipPart = Value.parseInteger(part); if (ipPart.isEmpty()) { return false; } if (ipPart.get() < 0 && ipPart.get() > 256) { return false; } } return true; } private  Utils(); static boolean isUUID(String uuid); static UUID toUUID(String uuid); static boolean isIpAddress(String ip); static String hostName(); static void quickSleep(); static String toString(Object instance, String... vars); static boolean equals(Object a, Object b); static int hashCode(Object instance, Object... objects);  }### Answer:
@Test public void checkersTest() { Assert.assertTrue(Utils.isIpAddress("127.0.0.1")); Assert.assertFalse(Utils.isIpAddress("a.b.c.d")); }