         return self
     }
     
-    @discardableResult public func verticalSpacing(_ constant: Float = 0, relatedBy: ((Int, Int) -> Bool) = (==), multiplier: Float = 1.0, priority: UILayoutPriority = UILayoutPriority.required) -> RelationLiteAutoLayout {
+    @objc @discardableResult public func verticalSpacing(_ constant: Float = 0, relatedBy: ((Int, Int) -> Bool) = (==), multiplier: Float = 1.0, priority: UILayoutPriority = UILayoutPriority.required) -> RelationLiteAutoLayout {
         guard let _ = secondItem else {
             return self
         }

    /// Set the view's layout attribute
    ///
    /// - returns: ItemLiteAutoLayout instance
    public func startLayout() -> ItemLiteAutoLayout {
        return ItemLiteAutoLayout(left: self, right: nil)
    }
    

        return self
    }
    
    @objc @discardableResult public func bottom(_ constant: Float = 0, relatedBy: ((Int, Int) -> Bool) = (==), multiplier: Float = 1.0, priority: UILayoutPriority = UILayoutPriority.required) -> RelationLiteAutoLayout {
        guard let _ = secondItem else {
            return self
        }
