@Override
    public void onResponse(@NonNull Call call, @NonNull Response response) {
        responseBody = response.body();
        if (response.isSuccessful()) {
            long contentLength = Preconditions.checkNotNull(responseBody).contentLength();
            stream = ContentLengthInputStream.obtain(responseBody.byteStream(), contentLength);
            callback.onDataReady(stream);
        } else {
            callback.onLoadFailed(new HttpException(response.message(), response.code()));
        }
    }
Fetches an {@link InputStream} using the okhttp library.
arms/src/main/java/com/jess/arms/http/OkHttpStreamFetcher.java