emitter.removeAllListeners([event])

//移除所有监听器   emitter.removeAllListeners()   //移除指定event的所有监听器   emitter.removeAllListeners('data')

EventEmitter.prototype.removeAllListeners = function(type) {   var key, listeners;   if (!this._events)     return this;   // not listening for removeListener, no need to emit   if (!this._events.removeListener) {     if (arguments.length === 0)       this._events = {};     else if (this._events[type])       delete this._events[type];     return this;   }   // emit removeListener for all listeners on all events   if (arguments.length === 0) {     for (key in this._events) {       if (key === 'removeListener') continue;       this.removeAllListeners(key);     }     this.removeAllListeners('removeListener');     this._events = {};     return this;   }   listeners = this._events[type];   if (util.isFunction(listeners)) {     this.removeListener(type, listeners);   } else {     // LIFO order     while (listeners.length)       this.removeListener(type, listeners[listeners.length - 1]);   }   delete this._events[type];   return this; };