Bind NSTreeController contentArray to model

NSTreeController+Binding.swift

final class ViewModel: NSObject {
    
    @objc var tree: [Node] = []
    
    override init() {
        super.init()
        
    }
}

final class ViewController: NSViewController {

    let viewModel = ViewModel()
    
    private(set) lazy var treeController: NSTreeController = {
        let treeController = NSTreeController()
        // …
        
        treeController.bind(
            NSBindingName("contentArray"),
            to: viewModel,
            withKeyPath: #keyPath(LibraryOutlineViewModel.tree),
            options: nil
        )
        return treeController
    }()

}

Do you think there is a way to have ViewModel that is non NSObject and still be able to do the binding?