We should update jtreg to a newer version of JUnit.

In addition to "Numerous bug fixes and minor improvements" compared to older versions the following feature would be a major win for writing parameterized tests:

> New @ParameterizedClass support that builds on @ClassTemplate and allows declaring a top-level or @Nested test class as a parameterized test class to be invoked multiple times with different arguments. The same @…​Source annotations supported with @ParameterizedTest may be used to provide arguments via constructor or field injection. Please refer to the User Guide for details: https://docs.junit.org/5.13.2/user-guide/index.html#writing-tests-parameterized-tests

Another feature is the new mechanism to report issues encountered during test discovery:

> Introduce a mechanism for TestEngine implementations to report issues encountered during test discovery. If an engine reports a DiscoveryIssue with a Severity equal to or higher than a configurable critical severity, its tests will not be executed. Instead, the engine will be reported as failed during execution with a failure message listing all critical issues. Non-critical issues will be logged but will not prevent the engine from executing its tests. The critical severity can be configured via a new configuration parameter and, currently, defaults to ERROR. Please refer to the User Guide for details: https://docs.junit.org/5.13.2/user-guide/index.html#running-tests-discovery-issues

Find the release notes of JUnit 5.13.2 downto 5.12.0 at https://docs.junit.org/5.13.2/release-notes/