docs: public @CheckForNull
      Obligation getObligationByType(ObjectType type) throws ClassNotFoundException {
          for (Iterator<Obligation> i = obligationIterator(); i.hasNext();) {
              Obligation obligation = i.next();
              if (Hierarchy.isSubtype(type, obligation.getType())) {
                  return obligation;
              }
          }
          return null;
      }