@VisibleForTesting
    static String parseHostMachine() {
        String hostMachine = System.getProperty("host_machine");
        return StringUtils.isNotEmpty(hostMachine) ? hostMachine : null;
    }
@Test
    public void parseHostMachine() {
        String old = System.getProperty("host_machine");
        try {
            System.setProperty("host_machine", "xxx");
            Assert.assertEquals("xxx", SystemInfo.parseHostMachine());
        } finally {
            if (old == null) {
                System.clearProperty("host_machine");
            } else {
                System.setProperty("host_machine", old);
            }
        }
        Assert.assertTrue(StringUtils.isEmpty(SystemInfo.getHostMachine()));
    }