Transformers

When working with RxJava, you may find yourself wanting to reuse pieces of an Observable or Flowable chain and somehow consolidate these operators into a new operator. Good developers find opportunities to reuse code, and RxJava provides this ability using ObservableTransformer and FlowableTransformer, which you can pass to the compose() operator.

ObservableTransformer

Bring back Google Guava as a dependency. In Chapter 3, Basic Operators, we covered the collect() operator and used it to turn  Observable<T> into a Single<ImmutableList<T>>. Effectively, we want to collect T emissions into a Google Guava ImmutableList<T>. Suppose we do this operation enough times until it starts...