* 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()
 * ```
 */
class MockWebServerRule : ExternalResource() {
  val server: MockWebServer = MockWebServer()

  override fun before() {

```
@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()

public final class mockwebserver3/junit4/MockWebServerRule : org/junit/rules/ExternalResource {
	public fun <init> ()V
	public final fun getServer ()Lmockwebserver3/MockWebServer;

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)
            rule.server