async function connect(token) {
  // if bot already exist, we disconnect
  if (this.bot) {
    await this.disconnect();
  }
  this.bot = new this.NodeTelegramBotApi(token, { polling: true });
  this.bot.on('error', (e) => {
    logger.debug(e);
  });
  this.bot.on('polling_error', async (e) => {
    logger.warn(`Telegram polling error, code = ${e.code}, message = ${e.message}`);
    if (e.code === 'ETELEGRAM' && e.message === 'ETELEGRAM: 404 Not Found') {
      await this.bot.stopPolling();
    }
  });
  this.bot.on('message', this.newMessage.bind(this));
}
@description Connect telegram API.
@param {string} token - Telegram API token.
@example
connect('test');