var react = require('react')
  var clock = {
    time: new Date()
  }
  setInterval(function() {
    // whoa, no need to call any silly .set() methods
    clock.time = new Date()
  }, 1000)
  react(clock).on('change', function(prop, newValue, oldValue) {
    console.log("The "+prop+" is now: " + newValue)
    // => the time is now Sat Jan 05 2013 11:38:31 GMT+0800 (SGT)
  })
  // alternatively, listen for particular property changes:
  react(clock).on('change time', function(newValue, oldValue) {
    console.log("The time is: " + newValue)
    // => the time is now Sat Jan 05 2013 11:38:31 GMT+0800 (SGT)
  })

  reactive(element, react(model))

// Emitter data type
function Stock(name, value) {
  this.name = name
  this.value = value
  react(this)
}
Stock.prototype = new Emitter()
var AAPL = new Stock('AAPL', 100)
AAPL.on('change value', function(value) {
  console.log('new value for '+ this.name +' is', value)
})

// Non-Emitter data type
function Stock(name, value) {
  this.name = name
  this.value = value
}
var AAPL = new Stock('AAPL', 100)
var stockListener = react(AAPL)
stockListener.on('change value', function(value) {
  // note the default value of `this` in this context is
  // a copy of the data source.
  console.log('new value for '+ this.name +' is', value)
})