@Override
  public Object get(PropertyKey key) {
    return get(key, ConfigurationValueOptions.defaults());
  }
@Test
  public void initConfWithExtenstionProperty() throws Exception {
    try (Closeable p = new SystemPropertyRule("alluxio.master.journal.ufs.option.a.b.c",
        "foo").toResource()) {
      resetConf();
      assertEquals("foo",
          mConfiguration.get(Template.MASTER_JOURNAL_UFS_OPTION_PROPERTY
              .format("a.b.c")));
    }
  }