public static FuryBuilder builder() {
    return new FuryBuilder();
  }
@Test
  public void testIgnoreFields() {
    Fury fury = Fury.builder().requireClassRegistration(false).build();
    IgnoreFields o = serDe(fury, new IgnoreFields(1, 2, 3));
    assertEquals(0, o.f1);
    assertEquals(0, o.f2);
    assertEquals(3, o.f3);
  }