optaplanner-core/src/main/java/org/optaplanner/core/config/heuristic/selector/entity/EntitySelectorConfig.java
public EntityDescriptor extractEntityDescriptor(HeuristicConfigPolicy configPolicy) {
        if (entityClass != null) {
            SolutionDescriptor solutionDescriptor = configPolicy.getSolutionDescriptor();
            EntityDescriptor entityDescriptor = solutionDescriptor.getEntityDescriptorStrict(entityClass);
            if (entityDescriptor == null) {
                throw new IllegalArgumentException("The selectorConfig (" + this
                        + ") has an entityClass (" + entityClass + ") that is not a known planning entity.\n"
                        + "Check your solver configuration. If that class (" + entityClass.getSimpleName()
                        + ") is not in the entityClassSet (" + solutionDescriptor.getEntityClassSet()
                        + "), check your " + PlanningSolution.class.getSimpleName()
                        + " implementation's annotated methods too.");
            }
            return entityDescriptor;
        } else if (mimicSelectorRef != null) {
            return configPolicy.getEntityMimicRecorder(mimicSelectorRef).getEntityDescriptor();
        } else {
            return null;
        }
    }
public EntityDescriptor extractEntityDescriptor(HeuristicConfigPolicy configPolicy) {
        if (entityClass != null) {
            SolutionDescriptor solutionDescriptor = configPolicy.getSolutionDescriptor();
            EntityDescriptor entityDescriptor = solutionDescriptor.getEntityDescriptorStrict(entityClass);
            if (entityDescriptor == null) {
                throw new IllegalArgumentException("The selectorConfig (" + this
                        + ") has an entityClass (" + entityClass + ") that is not a known planning entity.\n"
                        + "Check your solver configuration. If that class (" + entityClass.getSimpleName()
                        + ") is not in the entityClassSet (" + solutionDescriptor.getEntityClassSet()
                        + "), check your " + PlanningSolution.class.getSimpleName()
                        + " implementation's annotated methods too.");
            }
            return entityDescriptor;
        } else if (mimicSelectorRef != null) {
            return configPolicy.getEntityMimicRecorder(mimicSelectorRef).getEntityDescriptor();
        } else {
            return null;
        }
    }
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