Body:
The test_ParallelEventSync test uses threads to call limiter.CheckRateLimit("testMethod"). While this tests the rate limiter in a concurrent scenario, there is a potential race condition. The test checks assert limiter.counters["testMethod"] == 3 after all threads have joined. However, there's no guarantee that all threads have completely finished incrementing the counter before the assertion is made. A more robust approach would be to use a synchronization mechanism (e.g., a barrier or a lock) to ensure all threads have finished their operations before the assertion is checked. This will make the test more reliable and prevent occasional failures due to timing issues.