java.lang.IllegalArgumentException: The class (class org.optaplanner.core.impl.testdata.domain.lookup.TestdataObjectPrimitiveIntId) has a member (private final int org.optaplanner.core.impl.testdata.domain.lookup.TestdataObjectPrimitiveIntId.id) with a PlanningId annotation that returns a type (int) that does not implement Comparable.
Maybe use an Integer or String type instead.

	at org.optaplanner.core.config.util.ConfigUtils.findPlanningIdMemberAccessor(ConfigUtils.java:424)
	at org.optaplanner.core.impl.domain.lookup.LookUpStrategyResolver.lambda$determineLookUpStrategy$0(LookUpStrategyResolver.java:80)
	at java.util.concurrent.ConcurrentHashMap.computeIfAbsent(ConcurrentHashMap.java:1660)
	at org.optaplanner.core.impl.domain.lookup.LookUpStrategyResolver.determineLookUpStrategy(LookUpStrategyResolver.java:68)
	at org.optaplanner.core.impl.domain.lookup.LookUpManager.addWorkingObject(LookUpManager.java:48)