* Implementations must quickly dispatch callbacks to avoid creating a bottleneck.
 *
 * While [onReset] may occur at any time, the following callbacks are expected in order,
 * correlated by stream ID.
 *
 *  * [onRequest]
 *  * [onHeaders] (unless canceled)
 *  * [onData] (optional sequence of data frames)
 *
 * As a stream ID is scoped to a single HTTP/2 connection, implementations which target multiple

        }

        List<Exception> exceptionList = null;
        try {
            int count = 0;
            while (count < maxRetryCount) {
                if (listener != null) {
                    listener.onRequest(this, request, count);
                }

                try {
                    return client.execute(request);
                } catch (final MaxLengthExceededException e) {
                    throw e;

	_ = x[OpDisconnectClientMux-7]
	_ = x[OpDisconnectServerMux-8]
	_ = x[OpMuxClientMsg-9]
	_ = x[OpMuxServerMsg-10]
	_ = x[OpUnblockSrvMux-11]
	_ = x[OpUnblockClMux-12]
	_ = x[OpAckMux-13]
	_ = x[OpRequest-14]
	_ = x[OpResponse-15]
	_ = x[OpDisconnect-16]
	_ = x[OpMerged-17]
}

	// Only Stateful streams has flow control.
	OpUnblockClMux

	// OpAckMux acknowledges a mux was created.
	OpAckMux

	// OpRequest is a single request + response.
	// MuxID is returned in response.
	OpRequest

	// OpResponse is a response to a single request.
	// FlagPayloadIsErr is used to signify that the payload is a string error converted to byte slice.

    }
  }

  /** Returns once all stream actions complete successfully. */
  fun awaitSuccess() {
    val futureTask =
      results.poll(5, TimeUnit.SECONDS)
        ?: throw AssertionError("no onRequest call received")
    futureTask.get(5, TimeUnit.SECONDS)
  }