ios - Unwind Segues are not calling "prepareForSegue" in my mother view -

mother view -> child view (push) 

when perform manual unwind segue mother view, mother view's "prepareforsegue" not hit.

override func prepareforsegue(segue: uistoryboardsegue, sender: anyobject?) {         println(segue.identifier) //unwind segues don't print!  } @ibaction func unwindtotabbar(segue:uistoryboardsegue){ } 

the prepareforsegue unwind needs in child viewcontroller, because preparing return trip. destinationviewcontroller in case mother viewcontroller.