nodejs移除监听事件

//event.js 文件
var events = require('events');
var emitter = new events.EventEmitter();
//定义两个函数
var printsome1= function(arg1, arg2){
console.log('listener1', arg1, arg2);
}
var printsome2= function(arg1, arg2){
console.log('listener2', arg1, arg2);
}
emitter.on('someEvent', printsome1);
emitter.on('someEvent', printsome2);
//移除事件someEvent中的printsome1（移除的必须是已经注册过的事件）
emitter.removeListener('someEvent',printsome1);
emitter.emit('someEvent', 'arg1 参数', 'arg2 参数');