* the `@Rule` annotation:
 *
 * ```java
 * @Rule public final MockWebServerRule serverRule = new MockWebServerRule();
 * ```
 *
 * For Kotlin the `@JvmField` annotation is also necessary:
 *
 * ```kotlin
 * @JvmField @Rule val serverRule = MockWebServerRule()
 * ```
 */
@ExperimentalOkHttpApi
class MockWebServerRule : ExternalResource() {
  val server: MockWebServer = MockWebServer()

```
@Rule public final MockWebServerRule serverRule = new MockWebServerRule();
```

The `serverRule` field has a `server` field. It is an instance of `MockWebServer`. That instance
will be shut down automatically after the test runs.

For Kotlin, the `@JvmField` annotation is also necessary:

```
@JvmField @Rule val serverRule = MockWebServerRule()

import assertk.fail
import java.net.InetAddress
import java.net.UnknownHostException
import java.util.concurrent.CountDownLatch
import mockwebserver3.MockResponse
import mockwebserver3.junit4.MockWebServerRule
import okhttp3.AsyncDns
import okhttp3.HttpUrl.Companion.toHttpUrl
import okhttp3.OkHttpClient
import okhttp3.Request
import okhttp3.tls.HandshakeCertificates
import okhttp3.tls.HeldCertificate

import org.junit.Assert.fail
import org.junit.Test
import org.junit.runner.Description
import org.junit.runners.model.Statement

class MockWebServerRuleTest {
  @Test fun statementStartsAndStops() {
    val rule = MockWebServerRule()
    val called = AtomicBoolean()
    val statement: Statement =
      rule.apply(
        object : Statement() {
          override fun evaluate() {
            called.set(true)