Entrust and Verisign.

This is the behavior you'll get with your OkHttpClient if you don't specifically configure
`HandshakeCertificates`. Or you can do it explicitly with `addPlatformTrustedCertificates()`:

```java
HandshakeCertificates clientCertificates = new HandshakeCertificates.Builder()
    .addPlatformTrustedCertificates()
    .build();
OkHttpClient client = new OkHttpClient.Builder()

Backwards-Incompatible Changes
------------------------------

#### OkHttpClient final methods

`OkHttpClient` has 26 accessors like `interceptors()` and `writeTimeoutMillis()` that were non-final
in OkHttp 3.x and are final in 4.x. These were made non-final for use with mocking frameworks like
[Mockito][mockito]. We believe subtyping `OkHttpClient` is the wrong way to test with OkHttp. If

 * for background.
 */
@RunWith(AndroidJUnit4.class)
public class LetsEncryptTest {
  @Test public void getFailsWithoutAdditionalCert() throws IOException {
    OkHttpClient client = new OkHttpClient();

    boolean androidMorEarlier = Build.VERSION.SDK_INT <= 23;
    try {
      sendRequest(client, "https://valid-isrgrootx1.letsencrypt.org/robots.txt");
      if (androidMorEarlier) {
        fail();

 */
package okhttp3.brotli

import okhttp3.OkHttpClient
import okhttp3.Request

fun main() {
  val client =
    OkHttpClient.Builder()
      .addInterceptor(BrotliInterceptor)
      .build()

  sendRequest("https://httpbin.org/brotli", client)
  sendRequest("https://httpbin.org/gzip", client)
}

private fun sendRequest(
  url: String,
  client: OkHttpClient,
) {
  val req = Request.Builder().url(url).build()

package okhttp3

import java.io.IOException
import okhttp3.Authenticator.Companion.JAVA_NET_AUTHENTICATOR

/**
 * Do not use this.
 *
 * Instead, configure your OkHttpClient.Builder to use `Authenticator.JAVA_NET_AUTHENTICATOR`:
 *
 * ```
 *   val okHttpClient = OkHttpClient.Builder()
 *     .authenticator(okhttp3.Authenticator.Companion.JAVA_NET_AUTHENTICATOR)
 *     .build()
 * ```
 */

 * limitations under the License.
 */
package okhttp3.guide;

import java.io.IOException;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class GetExample {
  final OkHttpClient client = new OkHttpClient();

  String run(String url) throws IOException {
    Request request = new Request.Builder()
        .url(url)
        .build();

package okhttp3.recipes;

import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;
import okhttp3.WebSocket;
import okhttp3.WebSocketListener;
import okio.ByteString;

public final class WebSocketEcho extends WebSocketListener {
  private void run() {
    OkHttpClient client = new OkHttpClient.Builder()
        .readTimeout(0,  TimeUnit.MILLISECONDS)
        .build();

 * https://square.github.io/okhttp/
 */
@RunWith(AndroidJUnit4.class)
public class OkHttpClientTest {
  @Test public void get() throws IOException {
    OkHttpClient client = new OkHttpClient();
    Request request = new Request.Builder()
        .url("https://google.com/robots.txt")
        .build();
    try (Response response = client.newCall(request).execute()) {
      assertEquals(200, response.code());

 */
package okhttp3.recipes;

import java.io.IOException;
import java.util.concurrent.TimeUnit;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public final class PerCallSettings {
  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    Request request = new Request.Builder()

import java.io.IOException;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;

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 {