public static MarkdownParsingResult <T> SuccessWith <T>(this ITokenizer <IMdToken> tokenizer, T parsed)
 {
     return(MarkdownParsingResult <T> .Success(parsed, tokenizer));
 }
 public static MarkdownParsingResult <T> Fail <T>(this ITokenizer <IMdToken> tokenizer)
 {
     return(MarkdownParsingResult <T> .Fail <T>(tokenizer));
 }