public Map<String,Object> toMap() {
            Map<String,Object> map = new HashMap<String,Object>();
            map.put("id", this.id == null ? 0 : this.id);
            map.put("timestamp", this.timestamp == null ? new Date(0) : this.timestamp);
            map.put("class", this.clazz == null ? "" : this.clazz);
            map.put("operation", this.operation == null ? Types.EventOperation.UNRECOGNIZED : this.operation);
            map.put("ref", this.ref == null ? "" : this.ref);
            map.put("obj_uuid", this.objUuid == null ? "" : this.objUuid);
            map.put("snapshot", this.snapshot);
            return map;
        }