     
     override func sizeThatFits(size: CGSize) -> CGSize {
         var height: CGFloat = 0.0
-        for container in multicolumnManager.textContainers as! [NSTextContainer] {
+        for container in multicolumnManager.textContainers as [NSTextContainer] {
             height = max(height, multicolumnManager.usedRectForTextContainer(container).height)
         }
         return CGSize(width: size.width, height: height)


        while multicolumnManager.textContainers.count != Int(numberOfColumns) {
            if multicolumnManager.textContainers.count < Int(numberOfColumns) {
                let container = NSTextContainer(size: CGSize.zeroSize)
                container.lineFragmentPadding = 0.0
                multicolumnManager.addTextContainer(container)
                multicolumnManager.glyphRangeForTextContainer(container)

            }
        }
     
        for container in multicolumnManager.textContainers as [NSTextContainer] {
            container.size = CGSize(width: CGFloat(columnWidth), height: columnHeight)
        }
        
