External Role Mapper Implementation - Where should the JAR be stored?

[#1]

On-prem Apigee install, we are looking to enable external role mapping. The documentation says "... You need to create your own implementation of this class that reflects your respective groups. When finished place the compiled class in a JAR and put that JAR in your classpath."

Is there a specific folder in which the JAR should be located on the server? Or can it live alongside the other Apigee JAR files?

[david_ryan]

More specifically for version 4.16. Is there a place to put the jar like /opt/apigee/customer/application that doesn't getting affected by an upgrade?