ConstraintStateMachineType-ViewController.swift

public extension ConstraintStateMachineType where Self: UIViewController {
    // MARK: Properties
    var allConstraints: [NSLayoutConstraint] {
        return self.view.flatConstraints // helper function, recursively collects constraints
        // https://gist.github.com/pcperini/5a8ea37e8cbbe904a031
    }
    
    // MARK: Mutators
    func setNeedsUpdateConstraints() {
        self.view.setNeedsUpdateConstraints()
    }
}