code: func MarkdownCommonHighlighter(input []byte) []byte {
  	renderer := highlightHTMLRenderer{blackfriday.HtmlRenderer(commonHTMLFlags, "", ""), 0}
  	return blackfriday.MarkdownOptions(input, &renderer, blackfriday.Options{
  		Extensions: commonExtensions})
  }
docs: // MarkdownCommonHighlighter uses the blackfriday.MarkdownCommon setup but also includes
  // code-prettify formatting of BlockCode segments