if (mockWebServer == null) throw new IllegalStateException();

    ByteString state = randomToken();
    synchronized (this) {
      listeners.put(state, listener);
    }

    return slackApi.authorizeUrl(scopes, redirectUrl(), state, team);
  }

  private ByteString randomToken() {
    byte[] bytes = new byte[16];
    secureRandom.nextBytes(bytes);

      Types.newParameterizedType(Map.class, String.class, String.class));

  public void run() throws Exception {
    Map<String, String> requestBody = new LinkedHashMap<>();
    requestBody.put("longUrl", "https://publicobject.com/2014/12/04/html-formatting-javadocs/");
    RequestBody jsonRequestBody = RequestBody.create(
        mapJsonAdapter.toJson(requestBody), MEDIA_TYPE_JSON);