code: public boolean isExpired() {
  		if (getTimestamp() == null || getExpiresAfter() == 0) {
  			return false;
  		}
  		long expires = (getExpiresAfter() * 1000);
  		long now = Utils.timestamp();
  		return (getTimestamp() + expires) <= now;
  	}
docs: Checks if expired.
  @return true if expired