context.putUserData(CURRENT_ACCESSORS_OF_UPGRADED_PROPERTIES, diff(
            currentAccessorsOfUpgradedProperties(currentUpgradedProperties),
            currentAccessorsOfUpgradedProperties(baselineUpgradedProperties)
        ));
        context.putUserData(OLD_REMOVED_ACCESSORS_OF_UPGRADED_PROPERTIES, diff(

                ]
            }

            @Override
            <T> T getUserData(String key) {
                getUserData()[key]
            }

            @Override
            <T> void putUserData(String key, T value) {
                getUserData().put(key, value)
            }
        }
        rule
    }