TestSftpSubsystem(ChannelSession channel, SftpSubsystemConfigurator configurator) {
            super(channel, configurator)
        }

        @Override
        protected void doProcess(Buffer buffer, int length, int type, int id) throws IOException {
            int originalBufferPosition = buffer.rpos()

            int pos = buffer.rpos()
            def command = commandMessage(buffer, type)

	// at the same time high enough to start listing before we process
	// the whole page.
	chanSize := 2 * workersNumber
	if chanSize < 256 {
		chanSize = 256
	}
	toProcess := make(chan runtime.Object, chanSize)
	errs := make(chan error, workersNumber+1)
	workersExited := make(chan struct{})

	wg.Add(workersNumber)
	for i := 0; i < workersNumber; i++ {
		go func() {