docs: private boolean equivFields(JSField one, JSField two) {
      if (one instanceof JSDynamic) {
        return two instanceof JSDynamic;
      }
      else if (one instanceof JSEnum) {
        return two instanceof JSEnum;
      }
      else if (one instanceof JSPrimitive) {
        return (two instanceof JSPrimitive)
          && ((JSPrimitive)one).getTypeCode() == ((JSPrimitive)two).getTypeCode();
      }
      else if (one instanceof JSVariant) {
        // we assume without checking that JSVariants in this context must be boxed
        return (two instanceof JSVariant)
          && ((JSVariant)one).getBoxed().getID() == ((JSVariant)two).getBoxed().getID();
      }
      else
        return false;
    }