eventemitter4/doc/examples/7-toString.js

EventEmitter4 is an alternative to node's built-in EventEmitter class, and to the existing alternatives EventEmitter2 and EventEmitter3

var EventEmitter=require('../../index.js');
var emitter=new EventEmitter();

emitter.on('finished-eating',function() {});
emitter.on('finished-eating',function() {});
emitter.on('finished-eating',function() {});
emitter.on('finished-playing-ball',function() {});

console.log(emitter.toString());