// It returns empty configuration if its not set.
func (api objectAPIHandlers) GetBucketNotificationHandler(w http.ResponseWriter, r *http.Request) {
	ctx := newContext(r, w, "GetBucketNotification")

	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))

	vars := mux.Vars(r)
	bucketName := vars["bucket"]

	objAPI := api.ObjectAPI()
	if objAPI == nil {

			Queries("replication", "")
		// GetBucketVersioning
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.GetBucketVersioningHandler)).
			Queries("versioning", "")
		// GetBucketNotification
		router.Methods(http.MethodGet).
			HandlerFunc(s3APIMiddleware(api.GetBucketNotificationHandler)).
			Queries("notification", "")
		// ListenNotification
		router.Methods(http.MethodGet).

			// Register AbortMultipart Handler.
			bucket.Methods(http.MethodDelete).Path("/{object:.+}").HandlerFunc(api.AbortMultipartUploadHandler).Queries("uploadId", "{uploadId:.*}")
		case "GetBucketNotification":
			// Register GetBucketNotification Handler.
			bucket.Methods(http.MethodGet).HandlerFunc(api.GetBucketNotificationHandler).Queries("notification", "")
		case "PutBucketNotification":
			// Register PutBucketNotification Handler.