supportedV1Identifiers = Collections.unmodifiableSet(supportedDatatypes.keySet());
// the 2.0 datatypes
supportedDatatypes.put(DNSNameAttribute.identifier, new DNSNameAttributeProxy());
supportedDatatypes.put(IPAddressAttribute.identifier, new IPAddressAttributeProxy());
supportedV2Identifiers = Collections.unmodifiableSet(supportedDatatypes.keySet());
}