private void ScheduleUnreachable(UniqueAddress node)
{
if (_autoDownUnreachableAfter == TimeSpan.Zero)
{
DownOrAddPending(node);
}
else
{
var cancelable = Scheduler.ScheduleTellOnceCancelable(_autoDownUnreachableAfter, Self, new AutoDown.UnreachableTimeout(node), Self);
_scheduledUnreachable = _scheduledUnreachable.Add(node, cancelable);
}
}