protected HeaderExpression(string line, int level)
        {
            this.line = line;
            this.level = level;

            var parsed = new ParsedTextRun (line);

            content = parsed.GenerateCode ();

            ID = "h" + level.ToString () + "_" + Convert.ToBase64String (md5.ComputeHash (Encoding.Unicode.GetBytes (content))).Replace ('+', '-').Replace ('/', '_').Replace ('=', '_');
        }
            public override string GenerateCode()
            {
                var parsed = new ParsedTextRun (tokens);

                return "‘" + parsed.GenerateCode () + "’";
            }