/**
* Get the relative duration of this event, this will subtract the duration of sub-events. If the
* event is still active, the duration up till this point in time is returned, else it's the
* duration from {@link #start()} till {@link #stop()}'
*
* @return The relative duration of this event
*/
public long getDuration() {
long delta = 0;
for (PageEvent e : getSubEvents()) {
delta += e.getDuration();
}
return getDurationAbsolute() - delta;
}
