module.exports.extend = function(child, parent) {
  for (var key in parent) {
    if (hasProp.call(parent, key))
      child[key] = parent[key];
    }
  function ctor() {
    this.constructor = child;
  }
  ctor.prototype = parent.prototype;
  child.prototype = new ctor();
  child.__super__ = parent.prototype;
  return child;
}

hasProp = {}.hasOwnProperty;
module.exports.extend = function(child, parent) {
  for (var key in parent) {
    if (hasProp.call(parent, key))
      child[key] = parent[key];
    }
  function ctor() {
    this.constructor = child;
  }
  ctor.prototype = parent.prototype;
  child.prototype = new ctor();
  child.__super__ = parent.prototype;
  return child;
}

fix util.exports