code: func (wfe *WebFrontEndImpl) sendError(response http.ResponseWriter, logEvent *web.RequestEvent, prob *probs.ProblemDetails, ierr error) {
  	wfe.stats.Inc(fmt.Sprintf("HTTP.ProblemTypes.%s", prob.Type), 1)
  	web.SendError(wfe.log, probs.V1ErrorNS, response, logEvent, prob, ierr)
  }
docs: // sendError wraps web.SendError