docs: protected boolean combineRecursively( List<Privilege> list,
                                            Privilege[] privileges ) {
          boolean res = false;
  
          for (Privilege p : privileges) {
              if (p.isAggregate()) {
                  res = combineRecursively(list, p.getAggregatePrivileges());
              } else if (!contains(list, p)) {
                  list.add(p);
                  res = true;
              }
          }
          return res;
      }