         guard let toolbarItem = sender as? NSToolbarItem else { return }
         var viewController: NSViewController?
 
-        switch convertFromNSToolbarItemIdentifier(toolbarItem.itemIdentifier) {
+        switch toolbarItem.itemIdentifier.rawValue {
         case kToolbarItemIdentifierGeneral:
             viewController = GeneralViewController.shared
         case kToolbarItemIdentifierMute:

        return toolbarHeight
    }
}

// Helper function inserted by Swift 4.2 migrator.
private func convertFromNSToolbarItemIdentifier(_ input: NSToolbarItem.Identifier) -> String {
    return input.rawValue
}

// Helper function inserted by Swift 4.2 migrator.
private func convertToOptionalNSToolbarItemIdentifier(_ input: String?) -> NSToolbarItem.Identifier? {
    guard let input = input else { return nil }
    return NSToolbarItem.Identifier(rawValue: input)
}

        }
        window?.contentView?.addSubview(viewController.view)
        resizeWindowForContentView(view: viewController.view)
        toolbar.selectedItemIdentifier = NSToolbarItem.Identifier(rawValue: itemIdentifier)
    }

    func resizeWindowForContentView(view: NSView) {
