private ComplexEventChunk<StateEvent> generateDeleteEventChunk() {
        ComplexEventChunk<StateEvent> deleteEventChunk = new ComplexEventChunk<>();
        StateEvent stateEvent = new StateEvent(2, 0);
        StreamEvent deletingEvent = streamEventFactory.newInstance();
        deletingEvent.setOutputData(new Object[]{siddhiAppContext.getTimestampGenerator().currentTime()});
        stateEvent.addEvent(0, deletingEvent);
        deleteEventChunk.add(stateEvent);
        return deleteEventChunk;
    }
this class has a runnable which runs on a separate thread called by AbstractQueryableRecordTable and handles cache
expiry
modules/siddhi-core/src/main/java/io/siddhi/core/util/cache/CacheExpirer.java