@Override
    public void setCommonProcessor(Processor commonProcessor) {
        if (processorChain == null) {
            processStreamReceiver.setNext(commonProcessor);
        } else {
            processStreamReceiver.setNext(processorChain);
            processorChain.setToLast(commonProcessor);
        }
    }
StreamRuntime to represent Single streams. Ex: Streams to filter queries.
modules/siddhi-core/src/main/java/io/siddhi/core/query/input/stream/single/SingleStreamRuntime.java