How to use the bitgo.Errors.UnsupportedCoinError function in bitgo

function handleV2CoinSpecificREST(req: express.Request, res: express.Response, next: express.NextFunction) {
  const method = req.method;
  const bitgo = req.bitgo;

  try {
    const coin = bitgo.coin(req.params.coin);
    const coinURL = coin.url(createAPIPath(req));
    return redirectRequest(bitgo, method, coinURL, req, next);
  } catch (e) {
    if (e instanceof Errors.UnsupportedCoinError) {
      const queryParams = _.transform(
        req.query,
        (acc: string[], value, key) => {
          for (const val of _.castArray(value)) {
            acc.push(`${key}=${val}`);
          }
        },
        []
      );
      const baseUrl = bitgo.url(req.baseUrl.replace(/^\/api\/v2/, ''), 2);
      const url = _.isEmpty(queryParams) ? baseUrl : `${baseUrl}?${queryParams.join('&')}`;

      debug(`coin ${req.params.coin} not supported, attempting to handle as a coinless route with url ${url}`);
      return redirectRequest(bitgo, method, url, req, next);
    }