function sendTimedRequest(): void {
      requestsAttempted++;
      requestStartTime = Date.now();
      let isRequestAlive = true;
      const request = fetch(uri, init);
      const requestTimeout = setTimeout(() => {
        isRequestAlive = false;
        if (shouldRetry(requestsAttempted)) {
          warning(false, 'fetchWithRetries: HTTP timeout, retrying.');
          retryRequest();
        } else {
          reject(new Error(sprintf(
            'fetchWithRetries(): Failed to get response from server, ' +
            'tried %s times.',
            requestsAttempted
          )));
        }
      }, _fetchTimeout);

      request.then(response => {
        clearTimeout(requestTimeout);
        if (isRequestAlive) {
          // We got a response, we can clear the timeout.
          if (response.status >= 200 && response.status < 300) {
            // Got a response code that indicates success, resolve the promise.
            resolve(response);
          } else if (shouldRetry(requestsAttempted)) {
            // Fetch was not successful, retrying.
            // TODO(#7595849): Only retry on transient HTTP errors.
            warning(false, 'fetchWithRetries: HTTP error, retrying.'),
            retryRequest();
          } else {
            // Request was not successful, giving up.
            const error: any = new Error(sprintf(
              'fetchWithRetries(): Still no successful response after ' +
              '%s retries, giving up.',
              requestsAttempted
            ));
            error.response = response;
            reject(error);
          }
        }
      }).catch(error => {
        clearTimeout(requestTimeout);
        if (shouldRetry(requestsAttempted)) {
          retryRequest();
        } else {
          reject(error);
        }
      });
    }
Sends a request to the server that will timeout after `fetchTimeout`.
If the request fails or times out a new request might be scheduled.