GetInPlaceMap(): could it return a dict instead of a list?

I’m experiencing with GetInPlaceMap.
GetInPlaceMap does not return a dict as its name suggests but a list.
The doc says: "For each sub-shape ID of theShapeWhat return a list of corresponding sub-shape IDs of theShapeWhere. ".

Can I actually map the element of the list to the IDs of theShapeWhat’s sub-shapes?