 	func assignUnclaimedToolbarItems(_ toolbar: NSToolbar, handler: ToolbarItemHandler)
 }
 
-@available(macOS, introduced: 10.12)
+@available(macOS 10.12, *)
 extension ToolbarItemHandler {
 	func hookupToToolbarItems(_ handler: ToolbarItemHandler, window: NSWindow) {
 		//find owner

// This file should only be included in macOS targets
#if os(macOS)
import Cocoa
#endif

@available(macOS, introduced: 10.12)
protocol ToolbarItemHandler : class {
	///called by a top level controller for each toolbar item no one has claimed
	func handlesToolbarItem(_ item: NSToolbarItem) -> Bool

	}
}

//@available(macOS 10.12, *)
//fileprivate func firstChildViewController<T>(_ rootController: NSViewController) -> T?
//{
//	return firstRecursiveDescendent(rootController,
//									children: { return $0.childViewControllers },
//									filter: { return $0 is T }) as? T
//}

/// Use the following code in a NSWindowController subclass that is the toolbar's delegate

