### Question:
DateTimeUtils { public static String iso8601UTCFromDate(Date date) { if (date == null) { return ""; } TimeZone tz = TimeZone.getTimeZone("UTC"); DateFormat formatter = ISO8601_FORMAT.get(); formatter.setTimeZone(tz); String iso8601date = formatter.format(date); return iso8601date.replace("+0000", "+00:00"); } private  DateTimeUtils(); static String javaDateToTimeSpan(final Date date, Context context, long currentTime); static String javaDateToTimeSpan(final Date date, Context context); static Date dateFromIso8601(final String strDate); static Date dateUTCFromIso8601(String iso8601date); static String iso8601FromDate(Date date); static String iso8601UTCFromDate(Date date); @Deprecated static Date nowUTC(); @Deprecated static Date localDateToUTC(Date dtLocal); static int daysBetween(Date dt1, Date dt2); static int hoursBetween(Date dt1, Date dt2); static int minutesBetween(Date dt1, Date dt2); static int secondsBetween(Date dt1, Date dt2); static long millisecondsBetween(Date dt1, Date dt2); static boolean isSameYear(Date dt1, Date dt2); static boolean isSameMonthAndYear(Date dt1, Date dt2); static long timestampFromIso8601(final String strDate); static long timestampFromIso8601Millis(final String strDate); static Date dateFromTimestamp(long timestamp); static String iso8601FromTimestamp(long timestamp); static String iso8601UTCFromTimestamp(long timestamp); static String timeSpanFromTimestamp(long timestamp, Context context);  }### Answer:
@Test public void testIso8601UTCFromDate() { TimeZone.setDefault(TimeZone.getTimeZone("GMT+2:00")); Date date = new Date(mDefaultDate); String expected = "2019-07-30T10:54:18+00:00"; String actual = DateTimeUtils.iso8601UTCFromDate(date); assertThat(actual).isEqualTo(expected); }