extend_example.js

var extend = function(child) {
  var base = this;

  if(child) {
    for(var prop in child)  {
      base[prop] = child[prop];
    }

    for(var prop in child)  {
      base.prototype[prop] = child[prop];
    }
  }

  return base;
};

var Model = function()  {
  this.data = {};
}

Model.prototype.set = function(key, value) {
  this.data[key] = value;
}

Model.prototype.get = function(key)  {
  return this.data[key];
}

Model.extend = extend;