prow/tide/history/history.go
func (h *History) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	b, err := json.Marshal(h.AllRecords())
	if err != nil {
		logrus.WithError(err).Error("Encoding JSON history.")
		b = []byte("{}")
	}
	if _, err = w.Write(b); err != nil {
		logrus.WithError(err).Error("Writing JSON history response.")
	}
}
func (h *History) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	b, err := json.Marshal(h.AllRecords())
	if err != nil {
		logrus.WithError(err).Error("Encoding JSON history.")
		b = []byte("{}")
	}
	if _, err = w.Write(b); err != nil {
		logrus.WithError(err).Error("Writing JSON history response.")
	}
}
// ServeHTTP serves a JSON mapping from pool key -> sorted records for the pool.