### Question:
StringUtilsEx { public static boolean isValidIp(String ip) { if (ip != null && !ip.isEmpty()) { String ipValidityRegularExpression = "^(([1-9])|([1-9][0-9])|(1[0-9][0-9])|(2[0-4][0-9])|(25[0-5]))((\\.([0-9]|([1-9][0-9])|(1[0-9][0-9])|(2[0-4][0-9])|(25[0-5]))){3})$"; return ip.matches(ipValidityRegularExpression); } return false; }  static boolean isValidIp(String ip); static List<String> findSystemVariableString(String str); static List<String> splitByComma(String ipsString);  }### Answer:
@Test public void isValidIpTestCase2() { String ip = "255.256.255.255"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isFalse(); }
@Test public void isValidIpTestCase3() { String ip = "019.0.0.1"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isFalse(); }
@Test public void isValidIpTestCase4() { String ip = "211212"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isFalse(); }
@Test public void isValidIpTestCase5() { String ip = "192.0.0.1"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isTrue(); }
@Test public void isValidIpTestCase6() { String ip = "127.10.10.10"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isTrue(); }
@Test public void isValidIpTestCase7() { String ip = "196.0.0.72"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isTrue(); }
@Test public void isValidIpTestCase1() { String ip = "0.0.0.0"; log.info("Checking IP: " + ip); assertThat(StringUtilsEx.isValidIp(ip)).isFalse(); }