Code snippet example of how to use the new behavioral attached properties:
<controls:DataGrid ItemsSource="{StaticResource list}" AutoGenerateColumns="True" SelectionMode="Extended" themes:DataGridHelper.HorizontalMouseWheelScrollingEnabled="True" themes:DataGridHelper.SelectedCells="{Binding Path=myViewModelSourceList, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" />