public Double getSystemCpuLoad() {
        return getMXBeanValueAsDouble("SystemCpuLoad");
    }
@Test
    void ifOperatingSystemMXBeanReturnsNaNForSystemCpuLoadOnLaterCalls_CachedValueIsReturned() throws JMException {
        when(mBeanServer.getAttribute(objectName, "SystemCpuLoad")).thenReturn(0.7, Double.NaN, 0.5);

        assertThat(jobServerStats.getSystemCpuLoad()).isEqualTo(0.7);
        assertThat(jobServerStats.getSystemCpuLoad()).isEqualTo(0.7);
        assertThat(jobServerStats.getSystemCpuLoad()).isEqualTo(0.5);
    }