Take a look for this, from Fabrication Feature:

Notification extensions : Fabrication provides mediators to detect notification interests based on intent. You no longer need to declare notifications that your mediator is interested in with listNotificationInterests. Instead you simply write a handler function like, respondToChanged. Fabrication automatically interprets this as a mediator's interest in the "changed" notification name. This feature reduces the complexity in switch cases that can result in a Mediator's handleNotification.

Yes, I got the same question 1 hour before. now recognized that the method responsTOBlaBla automatically handle the notification with "BlaBla" in the framework.