public static boolean isFuture(String timestamp) {
    return !StringUtils.isEmpty(timestamp) && isFuture(Long.parseLong(timestamp));
  }
@Test
  public void isFuture() {
    String nextMinute = String.valueOf(Calendar.getInstance().getTimeInMillis() + 60000);
    String previousMinute = String.valueOf(Calendar.getInstance().getTimeInMillis() - 60000);
    assertTrue(DateUtils.isFuture(nextMinute));
    assertFalse(DateUtils.isFuture(previousMinute));
  }