@Contract("_, _ -> this")
  public HtmlBuilder appendWithSeparators(@NotNull HtmlChunk separator, @NotNull Iterable<? extends HtmlChunk> children) {
    boolean first = true;
    for (HtmlChunk child : children) {
      if (!first) {
        append(separator);
      }
      first = false;
      append(child);
    }
    return this;
  }
@Contract("_, _ -> this")
  public HtmlBuilder appendWithSeparators(@NotNull HtmlChunk separator, @NotNull Iterable<? extends HtmlChunk> children)