static SampleSender getInstance(RemoteSampleListener listener) 
{
        // Support original property name
        boolean holdSamples = JMeterUtils.getPropDefault("hold_samples", false);
        // Extended property name
        String type = JMeterUtils.getPropDefault("mode", "Standard");
        if (holdSamples || type.equalsIgnoreCase("Hold")) {
            HoldSampleSender h = new HoldSampleSender(listener);
            return h;
        } else if (type.equalsIgnoreCase("Batch")) {
            BatchSampleSender b = new BatchSampleSender(listener);
            return b;
        } else if (type.equalsIgnoreCase("Statistical")) {
            StatisticalSampleSender s = new StatisticalSampleSender(listener);
            return s;
        } else {
            StandardSampleSender s = new StandardSampleSender(listener);
            return s;
        }
}

Checks for the Jmeter property mode and returns the required class.