*/
  open fun onClosed(
    webSocket: WebSocket,
    code: Int,
    reason: String,
  ) {
  }

  /**
   * Invoked when a web socket has been closed due to an error reading from or writing to the
   * network. Both outgoing and incoming messages may have been lost. No further calls to this
   * listener will be made.
   */
  open fun onFailure(

     * canceled, even if this plan is canceled.
     */
    fun retry(): Plan?
  }

  /**
   * What to do once a plan has executed.
   *
   * If [nextPlan] is not-null, another attempt should be made by following it. If [throwable] is
   * non-null, it should be reported to the user should all further attempts fail.
   *
   * The two values are independent: results can contain both (recoverable error), neither

     * Multiple calls to this method may be made concurrently.
     */
    @Throws(IOException::class)
    abstract fun onStream(stream: Http2Stream)

    /**
     * Notification that the connection's peer's settings may have changed to [settings].
     * Implementations should take appropriate action to handle the updated settings.
     *

   *
   * By default OkHttp will attempt to retransmit request bodies when the original request fails
   * due to any of:
   *
   *  * A stale connection. The request was made on a reused connection and that reused connection
   *    has since been closed by the server.
   *  * A client timeout (HTTP 408).
   *  * A authorization challenge (HTTP 401 and 407) that is satisfied by the [Authenticator].

    backwards-incompatible changes in forthcoming releases.
 *  Fix: Don't crash loading the public suffix database resource in obfuscated builds.
 *  Fix: Don't silently ignore calls to `EventSource.cancel()` made from
    `EventSourceListener.onOpen()`.
 *  Fix: Enforce the max intermediates constraint when using pinned certificates with Conscrypt.