@Override
protected void requestUpstream(long capacity, boolean terminated, long elements) {
FallbackSubscriber fallbackSubscriber = this.fallbackSubscriber;
if (fallbackSubscriber == null) {
BackpressureUtils.getAndAdd(REQUESTED, this, elements);
super.requestUpstream(capacity, terminated, elements);
} else {
Subscription subscription = fallbackSubscriber.subscription;
if (subscription != null) {
subscription.request(elements);
}
}
}
