@Override
    public long currentTime() {
        if (siddhiAppContext.isPlayback()) {
            return lastEventTimestamp;
        } else {
            return System.currentTimeMillis();
        }
    }
List of listeners listening to this timestamp generator.
modules/siddhi-core/src/main/java/io/siddhi/core/util/timestamp/TimestampGeneratorImpl.java