code: public JSVariant[] getDominatedVariants() {
      if (dominated == null) {
        List dom = new ArrayList();
        getDominatedVariants(dom);
        dominated = (JSVariant[])dom.toArray(new JSVariant[0]);
      }
      return dominated;
    }
docs: Identify any variants that are descendents of this tuple, either directly, or via
  other tuples.  Used in MessageMap construction.