@Override
    public void process(ComplexEventChunk complexEventChunk) {
        if (trigger) {
            List<ComplexEventChunk> returnEventChunkList = new LinkedList<>();
            execute(complexEventChunk, returnEventChunkList);
            selector.process(returnEventChunkList);
        } else {
            if (preJoinProcessor) {
                nextProcessor.process(complexEventChunk);
            }
        }
    }
Process the handed StreamEvent.

@param complexEventChunk event chunk to be processed
modules/siddhi-core/src/main/java/io/siddhi/core/query/input/stream/join/JoinProcessor.java