if (parentsAlreadyFetched == false)
if ( !parentsAlreadyFetched)
  public Set getParents()  {    if (parentsAlreadyFetched == false)    {      this.parents = getSignet().getPersistentDB().getParents(this);      parentsAlreadyFetched = true;    }    return this.parents;    // return UnmodifiableSet.decorate(this.parents);  }