val certificateChainCleaner: CertificateChainCleaner?

  /**
   * Default call timeout (in milliseconds). By default there is no timeout for complete calls, but
   * there is for the connect, write, and read actions within a call.
   *
   * For WebSockets and duplex calls the timeout only applies to the initial setup.
   */
  @get:JvmName("callTimeoutMillis")
  val callTimeoutMillis: Int = builder.callTimeout