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.

      .certificatePinner(
          new CertificatePinner.Builder()
              .add("publicobject.com", "sha256/Vjs8r4z+80wjNcr1YKepWQboSIRi63WsWXhIMN+eWys=")
              .build())
      .build();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/robots.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {

/**
 * Create UNIX domain sockets for MockWebServer and OkHttp and connect 'em together. Note that we
 * cannot do TLS over domain sockets.
 */
public class ClientAndServer {
  public void run() throws Exception {
    File socketFile = new File("/tmp/ClientAndServer.sock");
    socketFile.delete(); // Clean up from previous runs.

    MockWebServer server = new MockWebServer();