@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.
     *
     * Methods to this method may be made concurrently with [onStream]. But a calls to this method
     * are serialized.
     */
    open fun onSettings(