public Event copyFrom(Event event) {
        timestamp = event.timestamp;
        System.arraycopy(event.data, 0, data, 0, data.length);
        isExpired = event.isExpired;
        return this;
    }
Event that is used external to Siddhi
modules/siddhi-core/src/main/java/io/siddhi/core/event/Event.java