}
                });
            }

            // Start all threads
            for (Thread t : threads) {
                t.start();
            }

            // Wait for completion
            for (Thread t : threads) {
                t.join();
            }

            // Verify thread safety - no unexpected exceptions

        for (int i = 0; i < threadCount; i++) {
            final int threadId = i;
            new Thread(() -> {
                try {
                    WebApiUtil.setObject("key" + threadId, "value" + threadId);
                    WebApiUtil.getObject("key" + threadId);
                    WebApiUtil.setError(400 + threadId, "Error " + threadId);
                    WebApiUtil.validate();
                } catch (Exception e) {

        // When - Multiple threads accessing trees concurrently
        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {
                try {
                    startLatch.await(); // Wait for all threads to be ready

                    for (int i = 0; i < opsPerThread; i++) {

        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {
                try {
                    for (int i = 0; i < opsPerThread; i++) {
                        byte[] data = String.format("Thread%d-Op%d", threadId, i).getBytes();
                        byte[] encrypted = context.encryptMessage(data, threadId * 100L + i);

                            }
                        }
                    }
                    long threadEnd = System.nanoTime();
                    totalTime.addAndGet(threadEnd - threadStart);

                } catch (InterruptedException e) {
                    Thread.currentThread().interrupt();
                } finally {
                    endLatch.countDown();
                }
            });

                }
            });
            readThreads[i].start();
        }

        // Wait for all threads
        for (Thread thread : updateThreads) {
            thread.join(5000);
        }
        for (Thread thread : readThreads) {
            thread.join(5000);
        }

        // Verify final state
        assertEquals(100, entry.getChildren().size());

        // Test thread safety
        final int threadCount = 10;
        final int docsPerThread = 10;
        final List<Thread> threads = new ArrayList<>();
        final AtomicInteger successCount = new AtomicInteger(0);

        for (int i = 0; i < threadCount; i++) {
            final int threadId = i;
            Thread thread = new Thread(() -> {

        // Trip circuit
        circuitBreaker.trip();
        Thread.sleep(100);

        long afterTripTime = circuitBreaker.getTimeSinceLastStateChange();
        assertTrue(afterTripTime >= 100, "Time should have advanced");
        assertTrue(afterTripTime < 200, "Time should be reasonable");

        // Reset circuit
        circuitBreaker.reset();
        Thread.sleep(50);

        for (int t = 0; t < threadCount; t++) {
            final int threadId = t;
            executor.submit(() -> {
                try {
                    for (int i = 0; i < operationsPerThread; i++) {
                        String sid = "thread-" + threadId + "-key-" + i;
                        byte[] key = keyManager.generateRandomKey(16);

                        // Store key

                Arrays.fill(dataArrays[i], (byte) i);

                threads[i] = new Thread(() -> {
                    digest.sign(dataArrays[index], 0, dataArrays[index].length, request, response);
                });
            }

            for (Thread t : threads) {
                t.start();
            }
            for (Thread t : threads) {
                t.join();
            }