for (Certificate certificate : chain.connection().handshake().peerCertificates()) {
        String pin = CertificatePinner.pin(certificate);
        if (denylist.contains(pin)) {
          throw new IOException("Denylisted peer certificate: " + pin);
        }
      }
      return chain.proceed(chain.request());
    }
  };

  private final OkHttpClient client = new OkHttpClient.Builder()

  }

  @Suppress("UNCHECKED_CAST")
  @Throws(SSLPeerUnverifiedException::class)
  override fun getPeerCertificates(): Array<Certificate> {
    return if (certificates.isEmpty()) {
      throw SSLPeerUnverifiedException("peer not authenticated")
    } else {
      certificates as Array<Certificate>
    }
  }

  @Throws(
    SSLPeerUnverifiedException::class,
  )
  override fun getPeerCertificateChain(): Array<X509Certificate> {

object Http2 {
  @JvmField
  val CONNECTION_PREFACE = "PRI * HTTP/2.0\r\n\r\nSM\r\n\r\n".encodeUtf8()

  /** The initial max frame size, applied independently writing to, or reading from the peer. */
  const val INITIAL_MAX_FRAME_SIZE = 0x4000 // 16384

  const val TYPE_DATA = 0x0
  const val TYPE_HEADERS = 0x1
  const val TYPE_PRIORITY = 0x2
  const val TYPE_RST_STREAM = 0x3
  const val TYPE_SETTINGS = 0x4

 *    from the peer.
 *
 * Web sockets may fail due to HTTP upgrade problems, connectivity problems, or if either peer
 * chooses to short-circuit the graceful shutdown process:
 *
 *  * **Canceled:** the web socket connection failed. Messages that were successfully enqueued by
 *    either peer may not have been transmitted to the other.
 *

   */
  fun handshake(): Handshake?

  /**
   * Returns the protocol negotiated by this connection, or [Protocol.HTTP_1_1] if no protocol
   * has been negotiated. This method returns [Protocol.HTTP_1_1] even if the remote peer is using
   * [Protocol.HTTP_1_0].
   */
  fun protocol(): Protocol

) {
  /** True if the request body need not complete before the response body starts. */
  internal var isDuplex: Boolean = false
    private set

  /** True if there was an exception on the connection to the peer. */
  internal var hasFailure: Boolean = false
    private set

  internal val connection: RealConnection
    get() = codec.carrier as? RealConnection ?: error("no connection for CONNECT tunnels")