CPWindowController loadSheet

- (void)loadWindow
{
    [super loadWindow];
    
    // It's impossible to load a CPDocModalWindow from nib, we work around this by 
    // checking if the loaded window has the correct stylemask, if not we create a new window
    // with the same size as the old one and set the content view reference to that of the old window
    if ([_window styleMask] !== CPDocModalWindowMask)
    {
        var contentView = [_window contentView];
        
        _window = [[CPWindow alloc] initWithContentRect:[[_window contentView] bounds] styleMask:CPDocModalWindowMask];
        [_window setContentView:contentView];
    }
}