@Test
  void nullValue() throws IOException {
    check(Parsers.parserAt(BsonNull.VALUE).getCurrentToken()).is(JsonToken.VALUE_NULL);
    check(Parsers.parserAt(BsonNull.VALUE).getText()).is(JsonToken.VALUE_NULL.asString());
  }
Validate different type conversions like {@code DateTime => Long => String}
criteria/mongo/test/org/immutables/criteria/mongo/bson4jackson/TypeConversionTest.java