* @param <T> return type
     * @param operation the operation to execute
     * @return operation result
     * @throws CIFSException if circuit is open or operation fails
     */
    public <T> T executeWithCircuitBreaker(Supplier<T> operation) throws CIFSException {
        // Backpressure control
        if (backpressureEnabled && requestSemaphore != null) {
            if (!requestSemaphore.tryAcquire()) {

        String result = circuitBreaker.executeWithCircuitBreaker(() -> "success");
        assertEquals("success", result, "Operation should succeed");
        assertEquals(State.HALF_OPEN, circuitBreaker.getState(), "Circuit should be in HALF_OPEN");

        // One more success should close the circuit (threshold is 2)
        circuitBreaker.executeWithCircuitBreaker(() -> "success2");