@Override
        public Map<String, Object> snapshot() {
            Map<String, Object> state = new HashMap<>();
            state.put("GroupByKeyEvents", groupByKeyEvents);
            state.put("ScheduledTime", scheduledTime);
            return state;
        }
Sends the collected unique outputs per group by key upon arrival of timer event from scheduler.

@param complexEventChunk Incoming {@link ComplexEventChunk}
modules/siddhi-core/src/main/java/io/siddhi/core/query/output/ratelimit/snapshot/GroupByPerSnapshotOutputRateLimiter.java