         tableView.endUpdates()
     }
 
-    @IBAction func toggleHiddenCell(sender: UISwitch?) {
+    @IBAction func toggleHiddenCell(sender: UISwitch) {
         tableView.beginUpdates()
         
-        if sender!.on {
+        if sender.on {
             isExtraRowShowing = true
         }
         else {

        tableView.endUpdates()
    }

// MARK: UITableViewDataSource protocol conformance

    override func numberOfSectionsInTableView(tableView: UITableView) -> Int {
        return numberOfSections

        
        if (indexPath.section == 0) && (indexPath.row == 1) // This is the cell to hide - change as you need
        {
            if (!isExtraRowShowing) {
                // Hide the cell by setting its row height to zero
                rowHeight = 0
            }
        }
        return rowHeight
