 // MARK: Stack
 
 public enum Stack {
-    case vertically, horizontally
+    case vertically, horizontally, leadingToTrailing
 }
 
 extension Stack: DoubleAttribute {

    var nsAttributes: (NSLayoutAttribute, NSLayoutAttribute) {
        switch self {
        case .horizontally: return (.left, .right)
        case .vertically: return (.top, .bottom)
        }
    }

        case .centerX: return .centerX
        case .left: return .left
        case .right: return .right
        case .leading: return .leading
        case .trailing: return .trailing
        }
    }
}
