code: func (ns *Namespace) Highlight(s interface{}, lang, opts string) (template.HTML, error) {
  	ss, err := cast.ToStringE(s)
  	if err != nil {
  		return "", err
  	}
  
  	highlighted, _ := ns.deps.ContentSpec.Highlight(ss, lang, opts)
  	return template.HTML(highlighted), nil
  }
docs: // Highlight returns a copy of s as an HTML string with syntax
  // highlighting applied.