code: private void addChildrenByRef(IdReferenceType idReference) {
          String id = idReference.getValue();
          if (id == null || id.isEmpty()) {
              log.debug("Invalid reference to policy or policyset ");
              return;
          }
  
          Object obj = policyFinder.lookup(id);
  
          if (obj instanceof PolicyType || obj instanceof PolicySetType) {
              children.add(obj);
          } else {
              log.debug("No policy/policyset found for the reference " + id);
          }
      }
docs: Retrieve policy/policyset from the policy finder and add to the children policy or policyset lists
  
  @param idReference