The example `nats.go` program prints event notification to console.

```
go run nats.go
2016/10/12 06:51:26 Connected
2016/10/12 06:51:26 Subscribing to subject 'bucketevents'

			if isDirObject(dobj.ObjectName) && dobj.VersionID == "" {
				dobj.VersionID = nullVersionID
			}
			dv := DeletedObjectReplicationInfo{
				DeletedObject: dobj,
				Bucket:        bucket,
				EventType:     ReplicateIncomingDelete,
			}
			scheduleReplicationDelete(ctx, dv, objectAPI)
		}

		eventName := event.ObjectRemovedDelete
		objInfo := ObjectInfo{
			Name:         dobj.ObjectName,

				DeleteMarkerMTime:     DeleteMarkerMTime{objInfo.ModTime},
				DeleteMarker:          objInfo.DeleteMarker,
				ReplicationState:      objInfo.ReplicationState(),
			},
			Bucket:    bucket,
			EventType: ReplicateIncomingDelete,
		}
		scheduleReplicationDelete(ctx, dobj, objectAPI)
	}

	// Remove the transitioned object whose object version is being overwritten.
	if !globalTierConfigMgr.Empty() {

`Optional[EenType]` is eigenlijk een snelkoppeling voor `Union[EenType, None]`, ze zijn equivalent.

Dit betekent ook dat je in Python 3.10 `EenType | None` kunt gebruiken:

//// tab | Python 3.10+

```Python hl_lines="1"
{!> ../../docs_src/python_types/tutorial009_py310.py!}
```

        final Map<String, Object> source = toLowerHyphen(searchLogEvent.toSource());
        source.put("_id", searchLogEvent.getId());
        // source.put("version_no", searchLogEvent.getVersionNo());
        source.put("event_type", searchLogEvent.getEventType());
        return source;
    }

    /**
     * Converts a map to lower hyphen case.
     *
     * @param source The source map.
     * @return The converted map.