@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()));
}