.addTrustedCertificate(letsEncryptCertificateAuthority)
        .addTrustedCertificate(entrustRootCertificateAuthority)
        .addTrustedCertificate(comodoRsaCertificationAuthority)
        // Uncomment if standard certificates are also required.
        //.addPlatformTrustedCertificates()
        .build();

    client = new OkHttpClient.Builder()

    // Skip hosts that we've visited many times.
    AtomicInteger hostnameCount = new AtomicInteger();
    AtomicInteger previous = hostnames.putIfAbsent(url.host(), hostnameCount);
    if (previous != null) hostnameCount = previous;
    if (hostnameCount.incrementAndGet() > 100) return;

    Request request = new Request.Builder()
        .url(url)
        .build();
    try (Response response = client.newCall(request).execute()) {

    this.slackApi = slackApi;
  }

  public void start() throws Exception {
    if (mockWebServer != null) throw new IllegalStateException();

    mockWebServer = new MockWebServer();
    mockWebServer.setDispatcher(this);
    mockWebServer.start(slackApi.port);
  }

  public HttpUrl newAuthorizeUrl(String scopes, String team, Listener listener) {
    if (mockWebServer == null) throw new IllegalStateException();

    @Override public Response intercept(Chain chain) throws IOException {
      for (Certificate certificate : chain.connection().handshake().peerCertificates()) {
        String pin = CertificatePinner.pin(certificate);
        if (denylist.contains(pin)) {
          throw new IOException("Denylisted peer certificate: " + pin);
        }
      }
      return chain.proceed(chain.request());
    }
  };

import okhttp3.Response;

public final class Authenticate {
  private final OkHttpClient client;

  public Authenticate() {
    client = new OkHttpClient.Builder()
        .authenticator((route, response) -> {
          if (response.request().header("Authorization") != null) {
            return null; // Give up, we've already attempted to authenticate.
          }

          System.out.println("Authenticating for response: " + response);