Method retryWhen

src/main/java/io/reactivex/rxjava3/core/Single.java:4538–4543

Re-subscribes to the current Single if and when the Publisher returned by the handler function signals a value. If the {@code Publisher

(@NonNull Function<? super Flowable<Throwable>, @NonNull ? extends Publisher<@NonNull ?>> handler)

     * @throws NullPointerException if {@code handler} is {@code null}
     */
    @CheckReturnValue
    @SchedulerSupport(SchedulerSupport.NONE)
    @NonNull
    public final Single<T> retryWhen(@NonNull Function<? super Flowable<Throwable>, @NonNull ? extends Publisher<@NonNull ?>> handler) {
        return toSingle(toFlowable().retryWhen(handler));
    }

    /**
     * Wraps the given {@link SingleObserver}, catches any {@link RuntimeException}s thrown by its