// CPU percent can be -1 if not available or other negative values in test environment
        assertTrue(cpuPercent >= -1);
        assertTrue(cpuPercent <= 100);
    }

    public void test_waitForNoWaitingThreads() {
        systemHelper.setSystemCpuCheckInterval(10L);
        systemHelper.waitForNoWaitingThreads();
        assertEquals(0, systemHelper.waitingThreadNames.size());
    }