Javascript prototypal inheritance.

gistfile1.js

var __extends = function (child, parent) {
  for (var p in parent) {
    if (Object.prototype.hasOwnProperty.call(parent, p)) {
      child[p] = parent[p];
    }
  }
  function __() {
    this.constructor = child;
  }

  __.prototype = parent.prototype;
  child.prototype = new __();
};