Rx/OkHttp Android file downloader

OkHttpFileDownloader.java

import java.io.File;
import io.reactivex.Single;
import io.reactivex.schedulers.Schedulers;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okio.BufferedSink;
import okio.BufferedSource;
import okio.Okio;

/**
 * Simple file downloader using OkHttp, Okio and RxJava2
 *
 * build.gradle dependencies:
 * compile 'io.reactivex.rxjava2:rxandroid:2.0.1'
 * compile 'io.reactivex.rxjava2:rxjava:2.0.1'
 * compile 'com.squareup.okhttp3:okhttp:3.7.0'
 *
 * @author Pär Amsen 04/2017
 */
public class OkHttpFileDownloader {
    private OkHttpClient client = new OkHttpClient();

    public Single<File> download(String url, File out) {
        return Single.<File>create(subscriber -> {
            Request request = new Request.Builder()
                    .url(url)
                    .build();

                Response response = client.newCall(request).execute();
                BufferedSource source = Okio.buffer(response.body().source());
                BufferedSink sink = Okio.buffer(Okio.sink(out));
                source.readAll(sink);
                source.close();
                sink.close();
                subscriber.onSuccess(out);
        }).subscribeOn(Schedulers.io());
    }
}

So basically the download never fails, right? 😂