*/
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

  companion object {
    /**
     * A DNS that uses [InetAddress.getAllByName] to ask the underlying operating system to
     * lookup IP addresses. Most custom [Dns] implementations should delegate to this instance.
     */
    @JvmField
    val SYSTEM: Dns = DnsSystem()

    private class DnsSystem : Dns {

   */
  @Throws(IOException::class)
  fun authenticate(
    route: Route?,
    response: Response,
  ): Request?

  companion object {
    /** An authenticator that knows no credentials and makes no attempt to authenticate. */
    @JvmField
    val NONE: Authenticator = AuthenticatorNone()

    private class AuthenticatorNone : Authenticator {
      override fun authenticate(

Here’s a [sample event listener](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEventsNonConcurrent.java) that prints each event with a timestamp.

```java
class PrintingEventListener extends EventListener {
  private long callStartNanos;

  private void printEvent(String name) {
    long nowNanos = System.nanoTime();
    if (name.equals("callStart")) {

 */
package okhttp3.internal.http2

import java.io.IOException
import okhttp3.internal.and
import okio.BufferedSink
import okio.BufferedSource
import okio.ByteString

/**
 * This class was originally composed from the following classes in
 * [Twitter Hpack][twitter_hpack].
 *
 *  * `com.twitter.hpack.HuffmanEncoder`
 *  * `com.twitter.hpack.HuffmanDecoder`
 *  * `com.twitter.hpack.HpackUtil`
 *

import okhttp3.mockwebserver.Dispatcher;
import okhttp3.mockwebserver.MockResponse;
import okhttp3.mockwebserver.MockWebServer;
import okhttp3.mockwebserver.RecordedRequest;
import okio.Buffer;
import okio.Okio;

public class SampleServer extends Dispatcher {
  private final SSLContext sslContext;
  private final String root;
  private final int port;

  public SampleServer(SSLContext sslContext, String root, int port) {

import okhttp3.curl.internal.commonRun
import okhttp3.curl.logging.LoggingUtil
import okhttp3.internal.platform.Platform
import okhttp3.logging.HttpLoggingInterceptor
import okhttp3.logging.LoggingEventListener

class Main : CliktCommand(name = NAME, help = "A curl for the next-generation web.") {
  val method: String? by option("-X", "--request", help = "Specify request command to use")

 * limitations under the License.
 */
package mockwebserver3

import okhttp3.ExperimentalOkHttpApi
import okhttp3.Headers

/** An HTTP request initiated by the server. */
@ExperimentalOkHttpApi
class PushPromise(
  val method: String,
  val path: String,
  val headers: Headers,
  val response: MockResponse,

 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package okhttp3.survey.types

import okio.ByteString

data class SuiteId(val id: ByteString?, val name: String) {
  fun matches(suiteId: SuiteId): Boolean {
    return id == suiteId.id || name.substring(4) == suiteId.name.substring(4)
  }

import mockwebserver3.Stream
import okhttp3.internal.http2.ErrorCode
import okhttp3.internal.http2.Http2Stream
import okio.buffer

/** Adapt OkHttp's internal [Http2Stream] type to the public [Stream] type. */
internal class RealStream(
  private val http2Stream: Http2Stream,
) : Stream {
  override val requestBody = http2Stream.getSource().buffer()
  override val responseBody = http2Stream.getSink().buffer()

  override fun cancel() {

import java.net.InetAddress
import okhttp3.Dns

/**
 * A network that always resolves two IP addresses per host. Use this when testing route selection
 * fallbacks to guarantee that a fallback address is available.
 */
class DoubleInetAddressDns : Dns {
  override fun lookup(hostname: String): List<InetAddress> {
    val addresses = Dns.SYSTEM.lookup(hostname)
    return listOf(addresses[0], addresses[0])
  }