code: func (b *Bot) Reply(to *Message, what interface{}, options ...interface{}) (*Message, error) {
  	// This function will panic upon unsupported payloads and options!
  	sendOpts := extractOptions(options)
  	if sendOpts == nil {
  		sendOpts = &SendOptions{}
  	}
  
  	sendOpts.ReplyTo = to
  
  	return b.Send(to.Chat, what, sendOpts)
  }
docs: // Reply behaves just like Send() with an exception of "reply-to" indicator.