function _Emitter (name) {

  this.callers = {};

}

​

  _Emitter.prototype.add = function () {

    this.callers[this.name] = true;

  };

​

  _Emitter.prototype.log = function () {

    console.log(JSON.stringify(this.callers));

  };

​

// inherited

function Emitter (name) {

  this.name = name;

}

​

Emitter.prototype = new _Emitter();

​

// tests

var common = new Emitter(),

    foo = new Emitter('foo'),

    bar = new Emitter('bar');

​

foo.add();

bar.add();

​

common.log();

​

​

// 

// Recource.on('update', '087td08d7t0d78td073y3y893y', function () {});

// 

// Recource.on('update', 'any', function () {});

//