public PackageManagerAct()
        {
            backend = PackageManagerFactory.GetBackend ();

            Configuration.PackageManagerSelected += HandlePackageManagerSelected;
        }
 private void HandlePackageManagerSelected(object sender, PackageManagerSelectedEventArgs e)
 {
     backend = PackageManagerFactory.GetBackend (e.SelectedBackend);
     Preferences.SelectedProvider = e.SelectedBackend;
 }