jtreg reports details about framework-based test results in "text/junit.txt" and "text/testng.txt" files. Both files use a slightly different format, as their frameworks provide different stats.

It would be beneficial, not only in an active conversion task to use JUnit's Jupiter API, to have jtreg create a comparison of the data and store it in a dediacted file sibling named `testng-junit-comparison.txt`.

Here's a draft of how such a comparison can be implemented: https://gist.github.com/lahodaj/a6535272ec275ffa394232657492218b