httpResp, err := client.Do(httpReq)
	if err != nil {
		return outBuffer.String(), err
	}
	cfg.previousResponse = httpResp

	echo.LatencyField.WriteForRequest(&outBuffer, requestID, fmt.Sprintf("%v", time.Since(start)))
	echo.ActiveRequestsField.WriteForRequest(&outBuffer, requestID, fmt.Sprintf("%d", c.e.ActiveRequests()))

	// Process the response.
	err = processHTTPResponse(requestID, httpResp, &outBuffer)