Наследование: PopupMenuBase
        public OptionsMenuViewModel(IPlayShellViewModel playShellViewModel) {
            _shellViewModel = playShellViewModel;
            _softwareUpdate = _shellViewModel.SoftwareUpdate;
            _factory = _shellViewModel.Factory;
            _settings = _shellViewModel.Settings;

            OptionsMenu = new OptionsMenu(this);

            this.SetCommand(x => x.OptionsMenuCommand).Subscribe(x => OptionsMenu.IsOpen = !OptionsMenu.IsOpen);
        }