Adding bus to parametrized elements iterative

[FelixMau]

Working towards #31
Adding busses by calling get_bus from Mapper iterative. Please confirm that each component within an Element should have the same busses.

Slightly related change: removed cls parameter from get_default and get bus since the class is stored in Mapper as adapter anyway.

Ps.: Sorry for missing pre-commit run.

[henhuy]

PR looks good to me. Good catch that you removed cls from Mapper class!
But I don't understand your question:

Please confirm that each component within an Element should have the same busses.

Could you explain it again? thx

[henhuy]

Mini request.
Rest looks very good IMO

[FelixMau]

PR looks good to me. Good catch that you removed cls from Mapper class! But I don't understand your question:

Please confirm that each component within an Element should have the same busses.

Could you explain it again? thx

Sure :) If one component ("each row within the scalars") within a Element would need different busses I would not be able to catch them because I call Mapper.get_busses() outside of the loop and with the last component.
I don't think this would be a problem and I've made that decision for a little runtime advantage and to not build large lists. The .get_bus function would not make any difference between the components. But if we would be changing this we could face some issues that are maybe not easy to debug?

[henhuy]

If one component ("each row within the scalars") within a Element would need different busses I would not be able to catch them because I call Mapper.get_busses() outside of the loop and with the last component.

Oh okay. You are right - and indeed this could be the very case!
Thus, it would be good if you could gather busses for each row in a process and concat and unique them later...