The JMC Agent project is currently set up a bit awkwardly. The maven.compiler.source and maven.compiler.target properties are set to 1.8 but we enforce a JDK 11 and also have a testcase that implicitly uses/tests JDK11 features. Maybe it is time now to fully bump the agent to Java 11 compliance?

Furthermore, the POM file could be cleaned up and a few maven plugins that are used could be bumped to more recent versions.