When using a setup similar to https://github.com/orther/optapy/blob/0240f744f592d964110c86d1054ce63cf8c38452/optapy-core/tests/test_inverse_relation.py#L13. I tried this code as well and it gives the same error.
I get an error:
org.optaplanner.optapy.OptaPyException: org.optaplanner.optapy.OptaPyException: A problem occurred when wrapping the python problem Maybe an annotation was passed an incorrect type (for example, @problem_fact_collection_property(str) on a function that return a list of int).
Help will be very much appreciated.