Problem with "before" model_validators

[daniel-thom]

Functions like this one are causing us an issue. We are constructing Line from an already-constructed Line_Common instance. The code fails because it expects a dict instead.

I think that the best solution is to make them mode="after" validators instead. I have found it to always be better to use after validators unless I really need to perform some manipulation before Pydantic has run its type conversions. If this function were an after validator then it self would always be a constructed model.

Would you be OK with such a change? We could submit a PR.

[PMeira]

Originally it was done with mode="after" and _fields_set = self.model_fields_set, but there was something from Pydantic that was breaking the logic. It could have been how defaults are handled, so we'd get back to #7.