private String setupAuthentication(String response) throws IOException, URISyntaxException {
    isStartup = false;
    // Pattern pattern = Pattern.compile("Auth=(?<AUTH>(.*?))$", Pattern.CASE_INSENSITIVE);
    // String auth = pattern.matcher(EntityUtils.toString(response.getEntity())).group();

    int startIndex = response.indexOf("Auth=") + "Auth=".length();
    int endIndex = response.indexOf("\n", startIndex);

    authorizationToken = response.substring(startIndex, endIndex).trim();
    return dispatchPost(
        new URI("https://play.google.com/music/listen?hl=en&u=0"), FormBuilder.getEmpty());
  }