How to save and restore position of secondary NSViewController

I don't know if there is a better way, but the problem here is that when the AutosaveName is set in Interface Builder, and the Window is open via a Segue, the window is open at a predefined location and the frame is saved, overwriting the last saved frame...
If you have a predefined position to the center of the screen, each time the window will be open, it will appear in the center and the position will be saved.
To avoid this, I set the AutosaveName in the Window Controller (Not in IB), after restoring the saved Frame:

Code Block 
class MyWindowController: NSWindowController {
    override func windowDidLoad() {
        super.windowDidLoad()
        let thewindow = window as! NSWindow
        /// restore position
        thewindow.setFrameUsingName("MyWindow")
        self.windowFrameAutosaveName = "MyWindow"
    }
}