private void CmdOpenPlayer(PlayerViewModel pvm)
        {
            MainWindowViewModel.AddWorkspace(pvm);
            pvm.OnOpen();

            OpenPlayerCommand.NotifyCanExecuteChanged();
        }
 private void CmdOpenPlayer(PlayerViewModel pvm)
 {
     ServerVM.Tabs.Add(pvm);
     pvm.RequestClose += PlayerViewModel_RequestClose;
     pvm.OnOpen();
     OpenPlayerCommand.NotifyCanExecuteChanged();
 }