event call

callee.js

var EventEmitter = require('events').EventEmitter;
var inherits = require('util').inherits;

var Callee = function(){};
inherits(Callee, EventEmitter);

var o = new Callee();

o.on('first', function(){
  console.log('first');
});
o.on('second', function(){
  console.log('second');
});

var o2 = new Callee();

o2.on('all', function(){
  console.log('all');
  console.log('emit o\'s first');
  o.emit('first');
  console.log('emit o\'s second');
  o.emit('second');
});

o2.emit('all');