default CompletableFuture<List<T>> collect(SubscriptionOption... options) {
        return collect(defaultSubscriberExecutor(), options);
    }
Collects the elements published by this {@link StreamMessage} with the specified
{@link SubscriptionOption}s. The returned {@link CompletableFuture} will be notified when the elements
are fully consumed.

<p>Note that if this {@link StreamMessage} was subscribed by other {@link Subscriber} already,
the returned {@link CompletableFuture} will be completed with an {@link IllegalStateException}.
core/src/main/java/com/linecorp/armeria/common/stream/StreamMessage.java