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

    try {
      return S3AUnderFileSystem.createInstance(new AlluxioURI(path), conf);
    } catch (AmazonClientException e) {
      throw Throwables.propagate(e);
    }
  }
@Test
  public void createInstanceWithPath() {
    UnderFileSystem ufs = mFactory1.create(mS3APath, mConf);
    assertNotNull(ufs);
    assertTrue(ufs instanceof S3AUnderFileSystem);
  }