code: func (b *Bot) Restrict(chat *Chat, member *ChatMember) error {
  	prv, until := member.Rights, member.RestrictedUntil
  
  	params := map[string]string{
  		"chat_id":    chat.Recipient(),
  		"user_id":    member.User.Recipient(),
  		"until_date": strconv.FormatInt(until, 10),
  	}
  
  	embedRights(params, prv)
  
  	respJSON, err := b.Raw("restrictChatMember", params)
  	if err != nil {
  		return err
  	}
  
  	return extractOkResponse(respJSON)
  }
docs: // Restrict let's you restrict a subset of member's rights until
  // member.RestrictedUntil, such as:
  //
  //     * can send messages
  //     * can send media
  //     * can send other
  //     * can add web page previews
  //