private void SelectVarieties()
{
var vm = new SelectVarietiesViewModel(_projectService.Project.Varieties, _selectedVarieties);
if (_dialogService.ShowModalDialog(this, vm) == true)
{
_selectedVarieties.Clear();
_selectedVarieties.UnionWith(vm.Varieties.Where(v => v.IsSelected).Select(v => v.DomainVariety));
GenerateGraph();
}
}