Im trying to get my NWJS app to load in the center of the screen. Its not working even though im using the proper manifest perimeters. It loads on the top left of the screen. Any suggestions?

{

    "name": "atomspace.calc",
    "description": "Calculator Application",
    "main": "./RESOURCES/INDEX.html",
    "version": "00.00.01",

    "window": {
        "icon": "./RESOURCES/VISUALS/FAVICON.png",
        "title": "AtomSpace Calculator App",
        "show_in_taskbar": true,
        "position": "center",
        "transparent": true,
        "resizable": false,
        "toolbar": false,
        "frame": false,

        "width": 400,
        "min_width": 400,
        "max-width": 400,

        "height": 500,
        "min_height": 500,
        "max_height": 500
    }

}