Map userData = [seenApiChanges: [] as Set]

        String getClassName() { return null }

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

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

        void putUserData(String key, Object value) {
            userData[key] = value
        }
    }

        }
    }

    @Override
    @SuppressWarnings("unchecked")
    public void execute(ViolationCheckContext context) {
        Map<String, Object> userData = (Map<String, Object>) context.getUserData();
        userData.put("acceptedApiChanges", acceptedApiChanges);
        userData.put("seenApiChanges", new HashSet<ApiChange>());
    }

    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_REMOVED_ACCESSORS_OF_UPGRADED_PROPERTIES]