You see, the fact that you don't find it useful, doesn't mean it isn't for others simple smile I can't share full example of code where I used it but possibilities are endless.
For starters (I'm android dev) I used "traits extending classes" to create "specific purpose traits of Android Fragments" - such as adding the EventBus connections or behavior that was useful in some cases where java's single inheritance model would make me sweat to find a nice solution.