How to use with turning on/off constraints

[imagemason]

So I've got some views that I want to move around in response to user interaction. To position them I have multiple constraints with different priorities - I can turn one or more constraints off and since there are still other constraints available the view (or whatever) moves to the new location. So normally I would do something like this:

self.settingsBottomConstraint.isActive = false
UIView.animate(withDuration: 0.5, delay: 0, options: [.curveEaseInOut], animations: {
self.brainView.layoutIfNeeded()
}, completion: nil)

How can I accomplish that using Spring? I've tried everything I can think of - it doesn't animate, just turns off the constraint without animation.

Two no good least weird looking things I've tried that doesn't work (I've tried many more):

self.settingsBottomConstraint.isActive = false
self.brainView.animateNext {
self.brainView.layoutIfNeeded()
}

or

self.brainView.animateNext {
self.settingsBottomConstraint.isActive = false
}

Help?! Surely I'm just doing it wrong?