[implementaion] why pass `PointerDeviceType` as a pointer ID, instead of using the real `PointerId`?

[Jing KE]

I read this method and felt confused:

public int GetPointerId(RoutedEventArgs e)
{
   if (e is PointerRoutedEventArgs)
      return (int)((PointerRoutedEventArgs)e).Pointer.PointerDeviceType;
    else if (e is HoldingRoutedEventArgs)
        return (int)((HoldingRoutedEventArgs)e).PointerDeviceType;
     return -1;
}

In the documentations of the methods Editor.Pointer*, the parameter pointerId is supposed to be the pointer id to pass, but in your implementation, you send the PointerDeviceType enum instead of the real pointer id.

May you explain why we should do this if there is any particular reason or is it documented somewhere else?