setUnifiedTitleAndToolBarOnMac does not work

// code placeholder
void hideWindowTitleBar(QMainWindow *window)
{
    window->setUnifiedTitleAndToolBarOnMac(true);    NSView* nativeView = reinterpret_cast<NSView*>(window->winId());
    NSWindow* nativeWindow = [nativeView window];    [nativeWindow setStyleMask:[nativeWindow styleMask] |
     NSWindowStyleMaskFullSizeContentView | NSWindowTitleHidden];
    [nativeWindow setTitlebarAppearsTransparent:YES];
    [nativeWindow center];
}