How to get IKImageEditPanel to work in swift

I know that I can double-click an IKImageView and bring up the edit panel. And in Objective C I can do this

- (IBAction)editPanel:(id)sender {
    IKImageEditPanel *editor = [IKImageEditPanel sharedImageEditPanel];
    [editor setFrameOrigin:NSMakePoint(400,200)];
    [editor setDataSource:imageView]; // Here imageView is your IKImageView.
    [editor makeKeyAndOrderFront:nil];
}

But, when I try to set the data source in swift, I get an error saying I can't assign this type of IKImageView! to a value of type IKImageEditPanelDataSource!

Here is my code:

@IBAction func adjustments(sender: NSToolbarItem) {
        let editor = IKImageEditPanel.sharedImageEditPanel()
        editor.setFrameOrigin(NSPoint(x: 400, y: 200))
        editor.dataSource = imageView //Error on this line
        editor.makeKeyAndOrderFront(nil)

    }

From the apple forums....

I needed to tell the IKImageView that it should conform to the IKImageEditPanelDataSource. (It does this already, but I had to explicitly say so to the quiet the compiler).

Outside of any class ...

extension IKImageView: IKImageEditPanelDataSource {


}