@Override
  public void setWeight(int id, IArc arc, int weight) throws EngineException {

    if (arc instanceof PreArc) {
      ruleManipulationBackend.setWeight(id, (PreArc) arc, weight);
    } else if (arc instanceof PostArc) {
      ruleManipulationBackend.setWeight(id, (PostArc) arc, weight);
    } else {
      warning("this isn't an arc");
    }
  }
  @Override
  public void setWeight(int id, UUID nacId, IArc arc, int weight) throws EngineException {

    ruleManipulationBackend.setWeight(id, nacId, arc, weight);
  }