```

#### Dispatcher

By default MockWebServer uses a queue to specify a series of responses. Use a
Dispatcher (`import okhttp3.mockwebserver.Dispatcher`) to handle requests using another policy. One natural policy is to
dispatch on the request path.
You can, for example, filter the request instead of using `server.enqueue()`.

```java
final Dispatcher dispatcher = new Dispatcher() {

    @Override

      if (context.executionException.isPresent) return@AfterEachCallback
      assertThat(data.readByteString().hex(), "Data not empty")
        .isEqualTo("")
    }

  // Mutually exclusive. Use the one corresponding to the peer whose behavior you wish to test.
  private val serverWriter =
    WebSocketWriter(
      isClient = false,
      sink = data,
      random = random,
      perMessageDeflate = false,

0002 0.554 callEnd
0001 0.624 responseBodyEnd
0001 0.624 connectionReleased
0001 0.624 callEnd
```

The `EventListener.Factory` also makes it possible to limit metrics to a subset of calls. This one captures metrics on a random 10%:

```java
class MetricsEventListener extends EventListener {
  private static final Factory FACTORY = new Factory() {
    @Override public EventListener create(Call call) {

        } else if (requestBody.isDuplex()) {
          logger.log("--> END ${request.method} (duplex request body omitted)")
        } else if (requestBody.isOneShot()) {
          logger.log("--> END ${request.method} (one-shot body omitted)")
        } else {
          var buffer = Buffer()
          requestBody.writeTo(buffer)

          var gzippedLength: Long? = null

    // order, not in increasing index order.
    val codePoints = mutableListOf<Int>()

    // consume all code points before the last delimiter (if there is one)
    //  and copy them to output, fail on any non-basic code point
    val lastDelimiter = string.lastIndexOf('-', limit)
    if (lastDelimiter >= pos) {
      while (pos < lastDelimiter) {

    // Add a string with zero slashes: resulting URL gains one slash.
    assertThat(base.newBuilder().addPathSegments("").build().encodedPath)
      .isEqualTo("/a/b/c/")
    assertThat(base.newBuilder().addPathSegments("d").build().encodedPath)
      .isEqualTo("/a/b/c/d")

    // Add a string with one slash: resulting URL gains two slashes.

      .isEqualTo(certificate.getIssuerX500Principal().name)
    assertThat(certificate.getIssuerX500Principal().name).matches(Regex("CN=[0-9a-f-]{36}"))
    assertThat(certificate.serialNumber).isEqualTo(BigInteger.ONE)
    assertThat(certificate.subjectAlternativeNames).isNull()
    val deltaMillis = 1000.0
    val durationMillis = TimeUnit.MINUTES.toMillis((60 * 24).toLong())
    assertThat(certificate.notBefore.time.toDouble())

import okhttp3.testing.PlatformRule
import org.junit.jupiter.api.Test

@Suppress("HttpUrlsUsage") // Don't warn if we should be using https://.
open class HttpUrlJvmTest {
  val platform = PlatformRule()

  /** This one's ugly: the HttpUrl's host is non-empty, but the URI's host is null. */
  @Test
  fun hostContainsOnlyStrippedCharacters() {
    val url = "http://>/".toHttpUrl()
    assertThat(url.host).isEqualTo(">")

          while (true) {
            val action = actions.poll() ?: break
            action(stream)
          }
        }
      }
      return@FutureTask null
    }
  }

  /** Returns once all stream actions complete successfully. */
  fun awaitSuccess() {
    val futureTask =
      results.poll(5, TimeUnit.SECONDS)
        ?: throw AssertionError("no onRequest call received")

    assertThat(response.body.string()).isEqualTo("abc")

    assertFailsWith<IllegalStateException> {
      response.peekBody(3)
    }
  }

  /**
   * Returns a new response body that refuses to be read once it has been closed. This is true of
   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)