[BUG]: Cannot run concurrency test

Hello, I'm opening this issue to raise the issue with Concurrency and the execution of the test by test-runner.

For example, I was not able to run this [test class](https://github.com/google/gson/blob/ceae88bd6667f4263bbe02e6b3710b8a683906a2/gson/src/test/java/com/google/gson/functional/ConcurrencyTest.java#L33) from the project [google/gson](https://github.com/google/gson.git).