printEvent("callEnd");
  }

  @Override public void dnsStart(Call call, String domainName) {
    printEvent("dnsStart");
  }

  @Override public void dnsEnd(Call call, String domainName, List<InetAddress> inetAddressList) {
    printEvent("dnsEnd");
  }

  ...
}
```

We make a couple calls:

```java
Request request = new Request.Builder()

  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    RequestBody requestBody = new RequestBody() {
      @Override public MediaType contentType() {
        return MEDIA_TYPE_MARKDOWN;
      }

      @Override public void writeTo(BufferedSink sink) throws IOException {
        sink.writeUtf8("Numbers\n");
        sink.writeUtf8("-------\n");

        .build();
  }

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("http://httpbin.org/delay/2") // This URL is served with a 2 second delay.
        .build();

    try (Response response = client.newCall(request).execute()) {
      System.out.println("Response completed: " + response);
    }
  }

  public static void main(String... args) throws Exception {

public final class PostFile {
  public static final MediaType MEDIA_TYPE_MARKDOWN
      = MediaType.get("text/x-markdown; charset=utf-8");

  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    File file = new File("README.md");

    Request request = new Request.Builder()
        .url("https://api.github.com/markdown/raw")
        .post(RequestBody.create(file, MEDIA_TYPE_MARKDOWN))

 * or Android SDKs.
 */
@RunWith(AndroidJUnit4.class)
public class IssueReproductionTest {
  @Test public void getFailsWithoutAdditionalCert() throws IOException {
    OkHttpClient client = new OkHttpClient();

    sendRequest(client, "https://google.com/robots.txt");
  }

  private void sendRequest(OkHttpClient client, String url) throws IOException {
    Request request = new Request.Builder()
            .url(url)

import okhttp3.tls.HandshakeCertificates;
import okhttp3.tls.HeldCertificate;

/**
 * Create an HTTPS server with a self-signed certificate that OkHttp trusts.
 */
public class HttpsServer {
  public void run() throws Exception {
    HeldCertificate localhostCertificate = new HeldCertificate.Builder()
        .addSubjectAlternativeName("localhost")
        .build();

  private final int port;

  public SampleServer(SSLContext sslContext, String root, int port) {
    this.sslContext = sslContext;
    this.root = root;
    this.port = port;
  }

  public void run() throws IOException {
    MockWebServer server = new MockWebServer();
    server.useHttps(sslContext.getSocketFactory(), false);
    server.setDispatcher(this);
    server.start(port);
  }

[Mockito](https://github.com/mockito/mockito):

1. Script the mocks.
2. Run application code.
3. Verify that the expected requests were made.

Here's a complete example:

```java
public void test() throws Exception {
  // Create a MockWebServer. These are lean enough that you can create a new
  // instance for every unit test.
  MockWebServer server = new MockWebServer();

  // Schedule some responses.

    return result
  }
}

internal data class AlgorithmIdentifier(
  /** An OID string like "1.2.840.113549.1.1.11" for sha256WithRSAEncryption. */
  val algorithm: String,
  /** Parameters of a type implied by [algorithm]. */
  val parameters: Any?,
)

internal data class AttributeTypeAndValue(
  /** An OID string like "2.5.4.11" for organizationalUnitName. */
  val type: String,
  val value: Any?,
)

    }

    @Override public void callStart(Call call) {
      printEvent("callStart");
    }

    @Override public void proxySelectStart(Call call, HttpUrl url) {
      printEvent("proxySelectStart");
    }

    @Override public void proxySelectEnd(Call call, HttpUrl url, List<Proxy> proxies) {
      printEvent("proxySelectEnd");
    }

    @Override public void dnsStart(Call call, String domainName) {