anchor.diff:    String writeHeader(Header header) {
       String inlines = writeInlines(header.contents);
       if (header is SetextHeader && header.level == 2) {
  -      return inlines + "\n" + (header.level == 1 ? '=' : '-') * inlines.length;
  +      return inlines + "\n" + (header.level == 1 ? '=' : '-') * inlines.length + "\n";
       }
       return "#" * header.level + " " + inlines + "\n";
     }
  
positive.code:     int index = list.startIndex;
      list.items.forEach((ListItem listItem) {
        String pad;
        String contents = writeBlocks(listItem.contents, list.tight);
        contents = contents.splitMapJoin("\n", onNonMatch: (String str) {
          if (pad == null) {
            String marker = index.toString() + list.indexSeparator.char + " ";
  
negative.code:     String result = "";
      list.items.forEach((ListItem listItem) {
        String pad;
        String contents = writeBlocks(listItem.contents, tight: list.tight, unorderedListChar: list.bulletType.char);
        contents = contents.splitMapJoin("\n", onNonMatch: (String str) {
          if (pad == null) {
            String marker = list.bulletType.char + " ";
  