     
     // MARK: Working with derived data
     
+    func openFolder() {
+        NSWorkspace.shared().selectFile(nil, inFileViewerRootedAtPath: self.derivedFolderUrl.path)
+    }
+    
     func deleteDerivedData(_ subfolder: String? = nil) {
         do {
             var url: URL = self.derivedFolderUrl

        var item: NSMenuItem = NSMenuItem.init(title: "Clear ALL", action: #selector(AppDelegate.deleteAll), keyEquivalent: "")
        menu.addItem(item)
        
        self.subDirectories = self.derivedFolderUrl.subDirectories
        self.menuItems = []
        for url: URL in self.subDirectories {

            menu.addItem(item)
            self.menuItems.append(item)
        }
        
        menu.addItem(NSMenuItem.separator())
        
        item = NSMenuItem.init(title: "Open folder ...", action: #selector(AppDelegate.openFolder), keyEquivalent: "")
        menu.addItem(item)
        
        self.statusItem?.popUpMenu(menu)
    }
