*/
@Override
public TimeInterval lifetime() {
final Event start = calendar().event(Event.Type.FIRST_TRADE_DATE);
final Event end = calendar().event(Event.Type.LAST_TRADE_DATE);
if (start.isNull() && end.isNull()) {
return TimeInterval.NULL;
}
return VALUES.newTimeInterval(
start.isNull() ? 0 : start.date().getMillis(),
end.isNull() ? 0 : end.date().getMillis());
}