if (typeof Object.create === ‘function’) {

// implementation from standard node.js 'util' module
module.exports = function inherits(ctor, superCtor) {
  ctor.super_ = superCtor
  ctor.prototype = Object.create(superCtor.prototype, {
    constructor: {
      value: ctor,
      enumerable: false,
      writable: true,
      configurable: true
    }
  });
};

} else {

// old school shim for old browsers
module.exports = function inherits(ctor, superCtor) {
  ctor.super_ = superCtor
  var TempCtor = function () {}
  TempCtor.prototype = superCtor.prototype
  ctor.prototype = new TempCtor()
  ctor.prototype.constructor = ctor
}

}