@Test
public void testConvertToReadableTime() throws Exception {

  Long timestamp = 1389125737000L;
  String readableTime = DateUtils.convertToReadableTime(timestamp);
  // expected format with tz set to utc
  SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  sdf.setTimeZone(TimeZone.getTimeZone("UTC"));
  //parse using formatter with TZ=local and format using above formatter with TZ=UTC
  Assert.assertEquals("2014-01-07 20:15:37",
      sdf.format(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").parse(readableTime)));
}