     
     static func fluidConstraints(arrViews: [UIView], alignAxis: String, vMargin: CGFloat, hMargin: CGFloat, iMargin: CGFloat) -> [NSLayoutConstraint] {
         
-        let arrConstraints: NSMutableArray = NSMutableArray(capacity: arrViews.count)
-        let dictViews: NSMutableDictionary = NSMutableDictionary()
+        var arrConstraints: [NSLayoutConstraint] = [NSLayoutConstraint](repeating: NSLayoutConstraint(), count: arrViews.count)
+        var dictViews: Dictionary<String, UIView> = Dictionary<String, UIView>()
         let isVertical = alignAxis.isEqual("V")
         
         let stringGlobalFormat: NSMutableString = NSMutableString(format: alignAxis + ":|-" + String(describing: isVertical ? vMargin : hMargin) + "-" as NSString)

            
            let stringLocalFormat = String(isVertical ? "H" : "V") + ":|-" + String(describing: isVertical ? hMargin : vMargin) + "-[" + stringKey + "]-" + String(describing: isVertical ? hMargin : vMargin) + "-|"
            
            arrConstraints.addObjects(from: NSLayoutConstraint.constraints(withVisualFormat: stringLocalFormat, options: NSLayoutFormatOptions(rawValue: 0), metrics: nil, views: dictViews as! [String : Any]))
        }
        
        var stringAppended: String = ""

            let stringKeyBefore: String = "view" + String(index-1)
            let stringKey: String = "view" + String(index)
            
            dictViews[stringKey] = view
            
            if index==0 {
                stringGlobalFormat.append("[" + stringKey + "]-" + String(describing: iMargin) + "-")
