@Disabled("currently fails docs inside docs")
  @Test
  public void docOfDoc() throws IOException {
    BsonModel model = DEFAULT.withDocument(new Document("key", new Document("realKey", 42)));
    writeThenRead(JacksonCodecs.registryFromMapper(mapper), mapper, model);
  }
TODO better handle native BSON container types (eg. Map / List) inside regular immutable objects
criteria/mongo/test/org/immutables/criteria/mongo/bson4jackson/JacksonCodecsTest.java