*/
interface Connection {
  /** Returns the route used by this connection. */
  fun route(): Route

  /**
   * Returns the socket that this connection is using. Returns an
   * [SSL socket][javax.net.ssl.SSLSocket] if this connection is HTTPS. If this is an HTTP/2
   * connection the socket may be shared by multiple concurrent calls.
   */
  fun socket(): Socket

import okhttp3.internal.concurrent.TaskRunner
import okhttp3.internal.connection.FastFallbackExchangeFinder
import okhttp3.internal.connection.ForceConnectRoutePlanner
import okhttp3.internal.connection.RealConnectionPool
import okhttp3.internal.connection.RealRoutePlanner
import okhttp3.internal.connection.RouteDatabase

/**
 * Manages reuse of HTTP and HTTP/2 connections for reduced network latency. HTTP requests that

  )

  override fun connectEnd(
    connection: Connection,
    route: Route,
    call: Call,
  ) {
    logEvent(ConnectionEvent.ConnectEnd(System.nanoTime(), connection, route, call))
  }

  override fun connectionClosed(connection: Connection) = logEvent(ConnectionEvent.ConnectionClosed(System.nanoTime(), connection))

  override fun connectionAcquired(
    connection: Connection,
    call: Call,
  ) {

    .url("https://publicobject.com/helloworld.txt")
    .build();

System.out.println("REQUEST 1 (new connection)");
try (Response response = client.newCall(request).execute()) {
  // Consume and discard the response body.
  response.body().source().readByteString();
}

System.out.println("REQUEST 2 (pooled connection)");
try (Response response = client.newCall(request).execute()) {
  // Consume and discard the response body.

      object : EventListener() {
        var socket: SSLSocket? = null
        var closed = false

        override fun connectionAcquired(
          call: Call,
          connection: Connection,
        ) {
          socket = connection.socket() as SSLSocket
        }

        override fun requestHeadersStart(call: Call) {
          if (closed) {
            throw IOException("fake socket failure")
          }

 */
fun interface Dns {
  /**
   * Returns the IP addresses of `hostname`, in the order they will be attempted by OkHttp. If a
   * connection to an address fails, OkHttp will retry the connection with the next address until
   * either a connection is made, the set of IP addresses is exhausted, or a limit is exceeded.
   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

    @Throws(IOException::class)
    fun proceed(request: Request): Response

    /**
     * Returns the connection the request will be executed on. This is only available in the chains
     * of network interceptors; for application interceptors this is always null.
     */
    fun connection(): Connection?

    fun call(): Call

    fun connectTimeoutMillis(): Int

    fun withConnectTimeout(
      timeout: Int,

/**
 * Performs either **preemptive** authentication before connecting to a proxy server, or
 * **reactive** authentication after receiving a challenge from either an origin web server or proxy
 * server.
 *
 * ## Preemptive Authentication
 *
 * To make HTTPS calls using an HTTP proxy server OkHttp must first negotiate a connection with
 * the proxy. This proxy connection is called a "TLS Tunnel" and is specified by

 * When making TLS connections with multiple [connection specs](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection-spec/), these are attempted in sequence until the TLS handshake succeeds.

### [Connections](https://square.github.io/okhttp/4.x/okhttp/okhttp3/-connection/)

When you request a URL with OkHttp, here's what it does:

    val recorded = server.takeRequest()
    assertThat(recorded.headers["Accept"]).isEqualTo("text/plain")
    assertThat(recorded.headers["Accept-Encoding"]).isEqualTo("gzip, x-gzip, deflate")
    assertThat(recorded.headers["Connection"]).isEqualTo("keep-alive")
    assertThat(recorded.headers["User-Agent"]!!).startsWith("Apache-HttpClient/")
  }