public static FuryBuilder builder() {
    return new FuryBuilder();
  }
@Test
  public void testExposeFields() {
    Fury fury = Fury.builder().requireClassRegistration(false).build();
    ImmutableMap<String, Integer> map1 = ImmutableMap.of("1", 1);
    ImmutableMap<String, Integer> map2 = ImmutableMap.of("2", 2);
    ExposeFields o = serDe(fury, new ExposeFields(1, 2, 3, map1, map2));
    assertEquals(1, o.f1);
    assertEquals(2, o.f2);
    assertEquals(0, o.f3);
    assertEquals(o.map1, map1);
    assertNull(o.map2);
  }