@Override
    public void receive(Event event) {
        if (event != null) {
            for (Sink sink : sinks) {
                if (sink.getHandler() != null) {
                    sink.getHandler().handle(event);
                } else {
                    sink.getMapper().mapAndSend(event);
                }
            }
        }
    }
Sink Callback is used to get {@link Event}s from Siddhi Streams using
{@link StreamJunction} and send them to {@link SinkMapper}s to do the mapping.
modules/siddhi-core/src/main/java/io/siddhi/core/stream/output/sink/SinkCallback.java