code: static Node getRootOfQualifiedName(Node qName) {
      for (Node current = qName; true; current = current.getFirstChild()) {
        if (current.isName() || current.isThis() || current.isSuper()) {
          return current;
        }
        checkState(current.isGetProp(), "Not a getprop node: ", current);
      }
    }
docs: Gets the root node of a qualified name. Must be either NAME, THIS or SUPER.