@Override
    public List<String> getAttributeNames() {
        if (attributeNamesCache == null) {
            attributeNamesCache = Arrays.asList(rdn.getAttributeNames());
        }
        return attributeNamesCache;
    }
@author Marc Savy {@literal <msavy@redhat.com>}
gateway/engine/core/src/main/java/io/apiman/gateway/engine/impl/DefaultLdapRdn.java