@CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    public final T blockingGet(T defaultValue) {
        ObjectHelper.requireNonNull(defaultValue, "defaultValue is null");
        BlockingMultiObserver<T> observer = new BlockingMultiObserver<T>();
        subscribe(observer);
        return observer.blockingGet(defaultValue);
    }