ConcurrentModificationException thrown from org.drools.modelcompiler.constraints.LambdaAccumulator.hashCode

CME is thrown from org.drools.modelcompiler.constraints.LambdaAccumulator.hashCode in OptaPlanner KIE Server extension tests. One of the failing tests is for example [1].

The executable model is switched on because the test creates SolverFactory from KieContainer [2], that is already compiler via a kie-maven-plugin - see the corresponding testing KJAR [3].

[1] https://github.com/kiegroup/droolsjbpm-integration/blob/master/kie-server-parent/kie-server-tests/kie-server-integ-tests-optaplanner/src/test/java/org/kie/server/integrationtests/optaplanner/OptaplannerIntegrationTest.java#L201
[2] https://github.com/kiegroup/droolsjbpm-integration/blob/master/kie-server-parent/kie-server-services/kie-server-services-optaplanner/src/main/java/org/kie/server/services/optaplanner/SolverServiceBase.java#L97
[3] https://github.com/kiegroup/droolsjbpm-integration/tree/master/kie-server-parent/kie-server-tests/kie-server-integ-tests-optaplanner/src/test/filtered-resources/kjars-sources/cloudbalance