logStream.close();
        // After close, the stream should not accept more writes
        // but PrintStream doesn't throw exceptions on write after close
    }

    @Test
    void testConcurrentAccess() throws InterruptedException {
        // Test thread safety of getInstance
        LogStream.setInstance(testStream);

        final LogStream[] instances = new LogStream[10];

            // Expected in test environment without proper server setup
        }

        assertDoesNotThrow(() -> channelManager.shutdown());
    }

    @Test
    void testConcurrentAccess() throws InterruptedException {
        // Test thread safety
        Thread[] threads = new Thread[10];
        for (int i = 0; i < threads.length; i++) {
            threads[i] = new Thread(() -> {