A new rule should be added for app migration to JBoss EAP 7.3, as followup of JBEAP-16483:
WHERE: HA Singleton application imports classes org.wildfly.clustering.singleton.SingletonPolicy,
org.jboss.msc.service.Service or org.jboss.msc.value.InjectedValue
PERFORM: hint the classes were deprecated by EAP 7.3, providing link to related section in EAP 7.3 Migration Guide