Helpers

extend.js

var extend = function (object) {
  var index, result = object;
  if (!object) return result;
  for (var source, sourceIndex = 1, length = arguments.length; sourceIndex < length; sourceIndex++) {
    source = arguments[sourceIndex];
    var skipProto = typeof source == 'function';
    for (index in source) {  
      if (!(skipProto && index == 'prototype')) {
        object[index] = source[index];
      }  
    }  
  };
  return result;
};

inherits.js

var inherits = function(ctor, superCtor) {
  ctor.super_ = superCtor;
  ctor.prototype = Object.create(superCtor.prototype, {
    constructor: {
      value: ctor,
      enumerable: false,
      writable: true,
      configurable: true
    }
  });
};

//ex. inherits(Honda, Car);