public @Nullable ElementStub getElementStub(String name, int index) {
    List<? extends Stub> stubs = getChildrenStubs();
    int i = 0;
    for (Stub stub : stubs) {
      if (stub instanceof ElementStub && name.equals(((ElementStub)stub).getName()) && i++ == index) {
        return (ElementStub)stub;
      }
    }
    return null;
  }
public @Nullable ElementStub getElementStub(String name, int index)