func (agg *Aggregator) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
agg.setupOnce.Do(agg.setup)
sendErr := func(statusCode int, err error) {
func (agg *Aggregator) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
agg.setupOnce.Do(agg.setup)
sendErr := func(statusCode int, err error) {