return upgradedProperties.stream()
            .flatMap(UpgradePropertiesRuleSetup::mapOldAccessorsOfUpgradedProperty)
            .collect(Collectors.toMap(Map.Entry::getKey, Map.Entry::getValue));
    }

    private static Stream<Map.Entry<AccessorKey, ReplacedAccessor>> mapOldAccessorsOfUpgradedProperty(UpgradedProperty upgradedProperty) {
        return upgradedProperty.getReplacedAccessors().stream()