### Required, can be `None` { #required-can-be-none }

You can declare that a parameter can accept `None`, but that it's still required. This would force clients to send a value, even if the value is `None`.

To do that, you can declare that `None` is a valid type but simply do not declare a default value:

* Add a **JSON Schema** for the response, in the OpenAPI *path operation*.
    * This will be used by the **automatic docs**.
    * It will also be used by automatic client code generation tools.

But most importantly:

  val url: HttpUrl =
    HttpUrl
      .Builder()
      .scheme(if (sslSocketFactory != null) "https" else "http")
      .host(uriHost)
      .port(uriPort)
      .build()

  /**
   * The protocols the client supports. This method always returns a non-null list that
   * contains minimally [Protocol.HTTP_1_1].
   */
  @get:JvmName("protocols")
  val protocols: List<Protocol> = protocols.toImmutableList()

But in many cases, you will want to run several worker processes at the same time.

### Multiple Processes - Workers { #multiple-processes-workers }

 *  New: `okhttp-sse` is an early preview of Server-Sent Events (SSE). This feature is incomplete
    and is only suitable for experimental use.
 *  New: MockWebServer now supports client authentication (mutual TLS). Call `requestClientAuth()`
    to permit an optional client certificate or `requireClientAuth()` to require one.
 *  New: `RecordedRequest.getHandshake()` returns the HTTPS handshake of a request sent to
    `MockWebServer`.

import java.security.cert.X509Certificate
import javax.net.ssl.SSLPeerUnverifiedException
import javax.net.ssl.SSLSession
import okhttp3.internal.toImmutableList

/**
 * A record of a TLS handshake. For HTTPS clients, the client is *local* and the remote server is
 * its *peer*.
 *
 * This value object describes a completed handshake. Use [ConnectionSpec] to set policy for new
 * handshakes.
 */
class Handshake internal constructor(

// The limit is set to allow for bursty behavior,
// but prevent requests to overload the server completely.
// Rejected clients are expected to retry.
const lockMutexWaitLimit = 1000

// lockRequesterInfo stores various info from the client for each lock that is requested.
type lockRequesterInfo struct {
	Name            string // name of the resource lock was requested for

        .build(),
    )
    server.enqueue(MockResponse())
    val dns = FakeDns()
    dns["fakeurl"] = client.dns.lookup(server.hostName)
    dns["www.fakeurl"] = client.dns.lookup(server.hostName)
    client =
      client
        .newBuilder()
        .dns(dns)
        .build()
    val call =
      client.newCall(
        Request
          .Builder()
          .url("http://fakeurl:" + server.port)

        props.setProperty("jcifs.smb.client.username", "testuser");
        props.setProperty("jcifs.smb.client.password", "testpass");
        props.setProperty("jcifs.smb.client.domain", "testdomain");
        props.setProperty("jcifs.netbios.hostname", "testhost");
        props.setProperty("jcifs.netbios.scope", "");
        props.setProperty("jcifs.smb.client.connTimeout", "35000");

        // Create a test witness client that uses our mock RPC client
        TestWitnessClient client = new TestWitnessClient(witnessServer, mockContext, mockRpc);

        TestNotificationListener listener = new TestNotificationListener();

        CompletableFuture<WitnessRegistration> future = client.registerForNotifications("\\\\server\\share", serverAddress, listener);