keyManager.storeSessionKey(sessionId, testKey, "AES");

        long initialAge = keyManager.getKeyAge(sessionId);
        assertTrue(initialAge >= 0 && initialAge < 100, "Initial age should be small");

        Thread.sleep(200);

        long laterAge = keyManager.getKeyAge(sessionId);
        assertTrue(laterAge >= 200, "Age should increase after delay");
    }

    @Test

    }

    /**
     * Get key age in milliseconds
     *
     * @param sessionId the session ID
     * @return age in milliseconds, or -1 if unknown
     */
    public long getKeyAge(String sessionId) {
        Long creationTime = keyCreationTimes.get(sessionId);
        if (creationTime == null) {
            return -1;
        }
        return System.currentTimeMillis() - creationTime;
    }