@Override
  public UnderFileSystem create(String path, UnderFileSystemConfiguration conf) {
    Preconditions.checkNotNull(path, "Unable to create UnderFileSystem instance:"
        + " URI path should not be null");

    if (checkOSSCredentials(conf)) {
      try {
        return OSSUnderFileSystem.createInstance(new AlluxioURI(path), conf);
      } catch (Exception e) {
        throw Throwables.propagate(e);
      }
    }

    String err = "OSS Credentials not available, cannot create OSS Under File System.";
    throw Throwables.propagate(new IOException(err));
  }
@Test
  public void createInstanceWithPath() {
    UnderFileSystem ufs = mFactory.create(mOssPath, mConf);
    Assert.assertNotNull(ufs);
    Assert.assertTrue(ufs instanceof OSSUnderFileSystem);
  }