@Override
  protected String getScheme() {
    return config.getScheme();
  }
@Test
  public void testGetScheme() {
    S3FileSystem s3FileSystem = new S3FileSystem(s3Config("s3"));
    assertEquals("s3", s3FileSystem.getScheme());

    s3FileSystem = new S3FileSystem(s3Config("other"));
    assertEquals("other", s3FileSystem.getScheme());
  }