code: @Reference(service = AuthData.class,
                 cardinality = ReferenceCardinality.OPTIONAL,
                 policy = ReferencePolicy.STATIC,
                 target = "(id=unbound)",
                 policyOption = ReferencePolicyOption.GREEDY)
      protected void setAuthData(ServiceReference<AuthData> ref) {
          authDataRef = ref;
      }
docs: Declarative Services method for setting the service reference for the default auth data
  
  @param ref reference to the service