@Test
public void testEmpty() throws IOException, SystemCheckException {

  File tempRoot = new File(TestConstant.BASE_OUTPUT_PATH.concat("root"));
  tempRoot.mkdir();
  try {
    WalChecker checker = new WalChecker(tempRoot.getAbsolutePath());
    assertTrue(checker.doCheck().isEmpty());
  } finally {
    FileUtils.deleteDirectory(tempRoot);
  }
}