Method compose

src/main/java/io/reactivex/rxjava3/core/Single.java:2632–2638

Transform a Single by applying a particular SingleTransformer function to it. This method operates on the Single itself whereas {@link #l

(@NonNull SingleTransformer<? super T, ? extends R> transformer)

     * @see <a href="https://github.com/ReactiveX/RxJava/wiki/Implementing-Your-Own-Operators">RxJava wiki: Implementing Your Own Operators</a>
     */
    @SuppressWarnings("unchecked")
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public final <@NonNull R> Single<R> compose(@NonNull SingleTransformer<? super T, ? extends R> transformer) {
        return wrap(((SingleTransformer<T, R>) Objects.requireNonNull(transformer, "transformer is null")).apply(this));
    }

    /**
     * Stores the success value or exception from the current {@code Single} and replays it to late {@link SingleObserver}s.