@Override
    public List<SingleStreamRuntime> getSingleStreamRuntimes() {
        List<SingleStreamRuntime> list = new ArrayList<SingleStreamRuntime>(1);
        list.add(this);
        return list;

    }
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