code: func (b *Bot) Ban(chat *Chat, member *ChatMember) error {
  	params := map[string]string{
  		"chat_id":    chat.Recipient(),
  		"user_id":    member.User.Recipient(),
  		"until_date": strconv.FormatInt(member.RestrictedUntil, 10),
  	}
  
  	respJSON, err := b.Raw("kickChatMember", params)
  	if err != nil {
  		return err
  	}
  
  	return extractOkResponse(respJSON)
  }
docs: // Ban will ban user from chat until `member.RestrictedUntil`.