https://developer.adobe.com/experience-manager/reference-materials/6-5/javadoc/org/apache/sling/discovery/TopologyEventListener.html
TopologyEventListener (The Adobe AEM Quickstart and Web Application.)
adobe aemquickstartwebapplication
https://sling.apache.org/apidocs/sling9/org/apache/sling/discovery/TopologyEventListener.html
TopologyEventListener (Apache Sling 9 API)
apache slingapi