@Override
  public TreeElement addInternal(TreeElement first,
                                 ASTNode last,
                                 @Nullable ASTNode anchor,
                                 @Nullable Boolean before) {
    TreeElement firstAdded = super.addInternal(first, last, anchor, before);
    TreeElement element = first;
    while (true) {
      if (ElementType.JAVA_CASE_LABEL_ELEMENT_BIT_SET.contains(element.getElementType())) {
        JavaSourceUtil.addSeparatingComma(this, element, ElementType.JAVA_CASE_LABEL_ELEMENT_BIT_SET);
        break;
      }
      if (element == last) break;
      element = element.getTreeNext();
    }
    return firstAdded;
  }
@Override
  public TreeElement addInternal(TreeElement first,
                                 ASTNode last,
                                 @Nullable ASTNode anchor,
                                 @Nullable Boolean before)