}

  /** See https://api.slack.com/methods/oauth.access. */
  public OAuthSession exchangeCode(String code, HttpUrl redirectUrl) throws IOException {
    HttpUrl url = baseUrl.newBuilder("oauth.access")
        .addQueryParameter("client_id", clientId)
        .addQueryParameter("client_secret", clientSecret)
        .addQueryParameter("code", code)
        .addQueryParameter("redirect_uri", redirectUrl.toString())
        .build();

    Request request = new Request.Builder()
            .url(url)
            .build();
    try (Response response = client.newCall(request).execute()) {
      assertTrue(response.code() == 200 || response.code() == 404);
      assertEquals(Protocol.HTTP_2, response.protocol());

      for (Certificate c: response.handshake().peerCertificates()) {
        X509Certificate x = (X509Certificate) c;

        .post(RequestBody.create(file, MEDIA_TYPE_MARKDOWN))
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      System.out.println(response.body().string());
    }
  }

  public static void main(String... args) throws Exception {
    new PostFile().run();
  }

        .post(requestBody)
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      System.out.println(response.body().string());
    }
  }

  public static void main(String... args) throws Exception {
    new PostStreaming().run();
  }

        .url("https://publicobject.com/robots.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      for (Certificate certificate : response.handshake().peerCertificates()) {
        System.out.println(CertificatePinner.pin(certificate));
      }
    }
  }

        for (int i = 0; i < responseHeaders.size(); i++) {
          System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
        }

        throw new IOException("Unexpected code " + response);
      }

      System.out.println(response.body().string());
    }
  }

  public static void main(String... args) throws Exception {
    new CustomTrust().run();
  }

        .connectionSpecs(Collections.singletonList(spec))
        .sslSocketFactory(customSslSocketFactory, trustManager)
        .build();
  }

  /**
   * Returns the VM's default SSL socket factory, using {@code trustManager} for trusted root
   * certificates.
   */
  private SSLSocketFactory defaultSslSocketFactory(X509TrustManager trustManager)
      throws NoSuchAlgorithmException, KeyManagementException {

        .url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      Headers responseHeaders = response.headers();
      for (int i = 0; i < responseHeaders.size(); i++) {
        System.out.println(responseHeaders.name(i) + ": " + responseHeaders.value(i));
      }

        .url("https://api.imgur.com/3/image")
        .post(requestBody)
        .build();

    try (Response response = client.newCall(request).execute()) {
      if (!response.isSuccessful()) throw new IOException("Unexpected code " + response);

      System.out.println(response.body().string());
    }
  }

  public static void main(String... args) throws Exception {
    new PostMultipart().run();
  }

    return mockWebServer.url("/oauth/");
  }

  /** When the browser hits the redirect URL, use the provided code to ask Slack for a session. */
  @Override public MockResponse dispatch(RecordedRequest request) {
    HttpUrl requestUrl = mockWebServer.url(request.getPath());
    String code = requestUrl.queryParameter("code");
    String stateString = requestUrl.queryParameter("state");