/city/traffic: call marketLane.setTraffic(n) directly, or
marketLane.connect('/city/traffic', 15000) to poll a JSON endpoint
(reads traffic, count, or agents). Also:
setNight(bool), setRain(bool) — Columbia weather, showers
arrive unannounced. Five doors: the Kettle, the Proof, Spine & Signal,
the Stem, the Lantern Bowl.