code: func (email *Email) SetTemplate(htmlTemplate string) {
  	email.rw.Lock()
  	defer email.rw.Unlock()
  
  	// parse email htmlTemplate, will panic if fails
  	email.template = template.Must(template.New("email").Funcs(
  		template.FuncMap{
  			"ts": func(e log.Entry) (ts string) {
  				ts = e.Timestamp.Format(email.timestampFormat)
  				return
  			},
  		},
  	).Parse(htmlTemplate))
  }
docs: // SetTemplate sets Email's html template to be used for email body