}

    private static Map<AccessorKey, ReplacedAccessor> mapOldAccessorsOfUpgradedProperties(List<UpgradedProperty> upgradedProperties) {
        return upgradedProperties.stream()
            .flatMap(UpgradePropertiesRuleSetup::mapOldAccessorsOfUpgradedProperty)
            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
    }