* Methods in this class must not lock FrameWriter. If a method needs to write a frame, create an
   * async task to do so.
   */
  inner class ReaderRunnable internal constructor(
    internal val reader: Http2Reader,
  ) : Http2Reader.Handler,
    () -> Unit {
    override fun invoke() {
      var connectionErrorCode = ErrorCode.INTERNAL_ERROR
      var streamErrorCode = ErrorCode.INTERNAL_ERROR