code: func (t *templateHandler) Lookup(name string) (tpl.Template, bool) {
  
  	if strings.HasPrefix(name, textTmplNamePrefix) {
  		// The caller has explicitly asked for a text template, so only look
  		// in the text template collection.
  		// The templates are stored without the prefix identificator.
  		name = strings.TrimPrefix(name, textTmplNamePrefix)
  
  		return t.applyTemplateInfo(t.text.Lookup(name))
  	}
  
  	// Look in both
  	if te, found := t.html.Lookup(name); found {
  		return t.applyTemplateInfo(te, true)
  	}
  
  	return t.applyTemplateInfo(t.text.Lookup(name))
  
  }
docs: // Lookup tries to find a template with the given name in both template
  // collections: First HTML, then the plain text template collection.