Add tests for Asn1Integer comparison and to_owned

        assert!(c_ref < a_ref);

    }

    #[test]

    fn integer_to_owned() {

        let a = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();

        let b = a.to_owned().unwrap();

        assert_eq!(

            a.to_bn().unwrap().to_dec_str().unwrap().to_string(),

            b.to_bn().unwrap().to_dec_str().unwrap().to_string(),

        );

        assert_ne!(a.as_ptr(), b.as_ptr());

    }

    #[test]

    fn integer_cmp() {

        let a = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();

        let b = Asn1Integer::from_bn(&BigNum::from_dec_str("42").unwrap()).unwrap();

        let c = Asn1Integer::from_bn(&BigNum::from_dec_str("43").unwrap()).unwrap();

        assert!(a == b);

        assert!(a != c);

        assert!(a < c);

        assert!(c > b);

    }

    #[test]

    fn object_from_str() {

        let object = Asn1Object::from_str("2.16.840.1.101.3.4.2.1").unwrap();