```
var myObject = {"myKey" : "myValue"}
typeof(myObject.myKey) returns `string`

myObject.myKey = "newValue"
console.log(myObject.myKey) prints newValue

```

This is the expected behavior. But, similar value writes do not work for document.cookie

```
typeof(document.cookie) returns `string`

```

But performing `document.cookie = "value=123"`, appends to `document.cookie` string rather than set its value to `value=123`

So, how is assignment to `document.cookie` overridden?