Declarative Shadow Variables: Struggles with overridden entities

[triceo]

Consider a situation which occurs in the old implementation of CVRPTW:

• Customer does not have arrivalTime. It doesn't need it, because it doesn't understand time windows.
• TimeWindowedCustomer extends Customer and brings arrivalTime variable.
• Customer has previousCustomer shadow, which TimeWindowedCustomer needs to compute its arrivalTime. Therefore this needs to be a source.

This currently results in an exception, because TimeWindowedCustomer doesn't see previousCustomer.arrivalTime, because previousCustomer is Customer and not TimeWindowedCustomer.

Attempts to solve this by overriding getter/setter for previousCustomer on TimeWindowedCustomer to provide TimeWindowedCustomer only results in a different runtime exception.

The issue will be resolved when the following code can be migrated to DSV, without changing the data model:

• https://github.com/TimefoldAI/timefold-solver-benchmarks/tree/main/src/main/java/ai/timefold/solver/benchmarks/examples/vehiclerouting
• https://github.com/TimefoldAI/timefold-solver-benchmarks/tree/main/src/main/java/ai/timefold/solver/benchmarks/examples/examination