warning: possible EventEmitter memory leak detected

You may encounter the following warning when using EventEmitter.

warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.

For now, if you want to suppress it, set 0 with setMaxListeners. See http://nodejs.org/api/events.html#events_emitter_setmaxlisteners_n.