code: public Map<String,Field> getFieldsPlusParents() {
          Map<String,Field> tmp = new HashMap<String,Field>();
          tmp.putAll(fields);
          if (extend != null && !extend.equals("")) {
              Struct parent = contract.getStructs().get(extend);
              tmp.putAll(parent.getFieldsPlusParents());
          }
          return tmp;
      }
docs: Returns a Map of the Fields belonging to this Struct and all its ancestors.
  Keys are the Field names.