     }
     
     private func addSpacingConstraints() -> [NSLayoutConstraint] {
-        // TEMP:
+        // FIXME: Don't create spacers when not necessary
         /*
         var constraints2 = [NSLayoutConstraint]()
         let _ = self.arrangedSubviews.reduce(nil as UIView?) { previous, current in

public enum StackViewDistribution {
    case Fill
    case FillEqually
    case FillProportionally
    case EqualSpacing
    case EqualCentering
}


}

public class StackView : UIView {
    public var axis: UILayoutConstraintAxis = .Horizontal {
        didSet { if axis != oldValue { self.invalidateLayout() } }
    }
    public var distribution: StackViewDistribution = .Fill {
        didSet { if distribution != oldValue { self.invalidateLayout() } }
    }
    public var alignment: StackViewAlignment = .Fill {
        didSet { if alignment != oldValue { self.invalidateLayout() } }
    }
    public var spacing: CGFloat = 0.0 {
        didSet { if spacing != oldValue { self.invalidateLayout() } }
    }
    // FIXME: Implement
    public var baselineRelativeArrangement = false {
        didSet { if baselineRelativeArrangement != oldValue { self.invalidateLayout() } }
    }
    // FIXME: Implement
    public var layoutMarginsRelativeArrangement = false {
        didSet { if layoutMarginsRelativeArrangement != oldValue { self.invalidateLayout() } }
    }
    
    private var stackConstraints = [NSLayoutConstraint]()
    private var invalidated = false
