Set<ApiChange> acceptedApiChanges = (Set<ApiChange>) context.getUserData().get("acceptedApiChanges");
        Set<ApiChange> seenApiChanges = (Set<ApiChange>) context.getUserData().get("seenApiChanges");
        Set<ApiChange> left = new HashSet<>(acceptedApiChanges);
        left.removeAll(seenApiChanges);
        if (!left.isEmpty()) {
            String formattedLeft = CollectionUtils.join("\n", left);

        return acceptOrReject(member, changes, rejection)
    }

    Violation acceptOrReject(JApiCompatibility member, List<String> changes, Violation rejection) {
        Set<ApiChange> seenApiChanges = (Set<ApiChange>) context.userData["seenApiChanges"]
        Set<AccessorKey> seenOldAccessorsOfUpgradedProperties = (Set<AccessorKey>) context.userData[SEEN_OLD_ACCESSORS_OF_UPGRADED_PROPERTIES]

abstract class AbstractContextAwareRuleSpecification extends Specification {
    @TempDir
    File testDir

    ViolationCheckContext context = new ViolationCheckContext() {
        Map userData = [seenApiChanges: [] as Set]

        String getClassName() { return null }

        Map<String, ?> getUserData() { return userData }

        Object getUserData(String key) {
            return userData[key]
        }