Zonemaster::LDNS::RR::DS - Type DS record
A subclass of Zonemaster::LDNS::RR, so it has all the methods of
    that class available in addition to the ones documented here.
  - keytag()
- Returns the keytag value.
- algorithm()
- Returns the algorithm number.
- digtype()
- Returns the numeric digest type.
- digest()
- Returns the cryptographic digest in binary form.
- hexdigest()
- Returns the cryptographic digest as a hexadecimal string.
- verify($other)
- Checks if the current object is derived from the other object (if it's a
      DNSKEY) or was derived from the same DNSKEY as the other object (if it's a
      DS). If used with any other type of RR, it always returns false.