}

    @Nested
    @DisplayName("Concurrency Tests")
    class ConcurrencyTests {

        @Test
        @DisplayName("Should handle concurrent received notifications")
        void testConcurrentReceived() throws InterruptedException {
            int threadCount = 10;
            CountDownLatch startLatch = new CountDownLatch(1);
            CountDownLatch endLatch = new CountDownLatch(threadCount);