### Question:
HelperUtils { public static boolean hasCorrectFormat(String input) { input = input.trim(); return PATTERN_DATEFORMAT.matcher(input).matches(); } private  HelperUtils(); static Long parseTimeString(String input); static String parseStringTs(long ts_Active); static String addZero(int no); static boolean hasCorrectFormat(String input); static void parseEntryValue(Context context, Integer defaultNo); static List<String[]> getLanguageList(String[] availableLanguages, Context context, Result result,
                                                 Messages msg); static boolean checkEmailAddressValidness(String[] mailAddressParts, String[] domainList); static String[] splitMailAddress(String mailAddress); static String getHeaderText(final MimeMessage message); static byte[] readLimitedAmount(InputStream data, int maxSize);  }### Answer:
@Test public void testHasCorrectFormat() { boolean correctFormat = HelperUtils.hasCorrectFormat("2013-12-12 12:12"); assertTrue(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-2-12 12:12"); assertTrue(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-12-2 12:12"); assertTrue(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-2-2 1:12"); assertTrue(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-12-12 12:2"); assertTrue(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("13-12-12 12:21"); assertFalse(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-- 12:21"); assertFalse(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-12-12 :21"); assertFalse(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2013-12-12 12:21"); assertFalse(correctFormat); correctFormat = HelperUtils.hasCorrectFormat("2x, 2h"); assertFalse(correctFormat); }