public static float getMem() {
        return (float) (1
                - (double) OperatingSystemBeanManager.getFreePhysicalMem() / (double) OperatingSystemBeanManager.getTotalPhysicalMem());
    }
@Test
    public void testGetMem() {
        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(123L);
        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getTotalPhysicalMem()).thenReturn(2048L);
        assertEquals(EnvUtil.getMem(), 1 - ((double) 123L / (double) 2048L));

        systemBeanManagerMocked.when(() -> OperatingSystemBeanManager.getFreePhysicalMem()).thenReturn(0L);
        assertEquals(EnvUtil.getMem(), 1 - ((double) 0L / (double) 2048L));
    }