                 let label = viewController.preferencesTitle()
                 let icon = viewController.preferencesIcon()
                 
-                var toolbarItem = NSToolbarItem(itemIdentifier: identifier as String)
+                let toolbarItem = NSToolbarItem(itemIdentifier: identifier as String)
                 toolbarItem.label = label
                 toolbarItem.paletteLabel = label
                 toolbarItem.image = icon

    
    // MARK: - Constructors

    /// Initialize a new preferences window controller.
    init() {
        
        super.init(window: CCNPreferencesWindow())
                
    }
    
    /// Initializes a new preferences window controller with the given coder

    
    func segmentedControlAction(control: NSSegmentedControl) {
        
        if  let cell = control.cell as? NSSegmentedCell {
            
            let viewController = viewControllers[cell.tagForSegment(control.selectedSegment)]
            
