How to compare Object.create()?

Using `Object.create` method to create object.
How to compare them for equality or deep equality?

Use `Object.getPrototypeOf`?

e.g.

``` js
var a = Object.create(null);
var b = Object.create({});
assert.deepEqual(a, b);

var a = Object.create({});
var b = Object.create({a:233});
assert.deepEqual(a, b);
```
