@Override
  public void mount(AlluxioURI alluxioPath, AlluxioURI ufsPath, MountPOptions options)
      throws IOException, AlluxioException {
    mDelegatedFileSystem.mount(alluxioPath, ufsPath, options);
  }
@Test
  public void mount() throws Exception {
    FileSystem fileSystem = new DelegatingFileSystem(mMockFileSystem);
    AlluxioURI alluxioPath = new AlluxioURI("/t");
    AlluxioURI ufsPath = new AlluxioURI("/u");
    MountPOptions mountOptions = MountPOptions
        .newBuilder()
        .setReadOnly(false)
        .setShared(false)
        .build();
    fileSystem.mount(alluxioPath, ufsPath, mountOptions);
    Mockito.verify(mMockFileSystem, atLeastOnce())
        .mount(eq(alluxioPath), eq(ufsPath), eq(mountOptions));
  }