toStringNSLayoutAttribute

extension NSLayoutAttribute {
    func toString() -> String {
        switch self {
        case .Left: return "Left"
        case .Right: return "Right"
        case .Top: return "Top"
        case .Bottom: return "Bottom"
        case .Leading: return "Leading"
        case .Trailing: return "Trailing"
        case .Width: return "Width"
        case .Height: return "Height"
        case .CenterX: return "CenterX"
        case .CenterY: return "CenterY"
        case .LastBaseline: return "LastBaseline"
        case .FirstBaseline: return "FirstBaseline"
        case .LeftMargin: return "LeftMargin"
        case .RightMargin: return "RightMargin"
        case .TopMargin: return "TopMargin"
        case .BottomMargin: return "BottomMargin"
        case .LeadingMargin: return "LeadingMargin"
        case .TrailingMargin: return "TrailingMargin"
        case .CenterXWithinMargins: return "CenterXWithinMargins"
        case .CenterYWithinMargins: return "CenterYWithinMargins"
        case .NotAnAttribute: return "NotAnAttribute"
        }
    }
}