In RxJava, there is a set of operators we have not covered yet called blocking operators. These operators serve as an immediate proxy between the reactive world and the stateful one, blocking and waiting for results to be emitted, but returned in a non-reactive way. Even if the reactive operations are working on different threads, blocking operators will stop the declaring thread and make it wait for the results in a synchronized manner, much like blockingSubscribe().
Blocking operators are especially helpful in making the results of an Observable or Flowable easily available for evaluation. However, you will want to avoid using them in production because they encourage anti-patterns and undermine the benefits of reactive programming. For testing, you will still want to prefer TestObserver and TestSubscriber, which we will cover later. But here are the blocking...
