Transaction for entities proceeded by RXJava observer with DBFlow

[quillalady]

DBFlow Version: 5.0.0-alpha1

Bug or Feature Request: Question

Description:

How to use DBFlow transaction for RXJava observer so that the transaction is for whole stream of items proceeded by the observer? My attempt is:

new Observer<Item>() {
          @Override
          public void onSubscribe(@NonNull Disposable d) {
            FlowManager.getDatabase(AppDatabase.class).beginTransaction();
          }

          @Override
          public void onNext(@NonNull Item item) {
            FlowManager.getModelAdapter(Item.class).save(item, FlowManager.getDatabase(AppDatabase.class));
          }

          @Override
          public void onError(@NonNull Throwable error) {
          }

          @Override
          public void onComplete() {
            FlowManager.getDatabase(AppDatabase.class).endTransaction();
          }
        };

But beginTransaction() blocks processing of items.