@Test
  void regexpPattern() throws IOException {
    check(Parsers.parserAt(new BsonRegularExpression("abc")).getText()).is("abc");
    check(Parsers.parserAt(new BsonRegularExpression(".*")).getText()).is(".*");
  }
Validate different type conversions like {@code DateTime => Long => String}
criteria/mongo/test/org/immutables/criteria/mongo/bson4jackson/TypeConversionTest.java