Example

gistfile1.txt

CATransaction.begin()
CATransaction.setCompletionBlock({
    // Every animation added to this transaction is now finished
})

UIView.animateWithDuration(0.5, delay: 0.5, options: [], animations: {
    view1.alpha = 1.0
}, completion: { finished in
    self.addSeveralLayerAnimations()
})

CATransaction.commit()

/*
What I would like to say now:
*/
let animations = CATransaction.animations // layer and animation keys