Hm, i'm not sure that we want all of those methods. The problem is that when you instantiate custom_data for the first time, it still isn't materialized, so it only has the **:href** property. 

There would be a difference between the next two (first one when the resource isn't materialized, the second when it is)
```ruby
account.custom_data.has_key? "created_at"? #=> false
```
```ruby
account.custom_data["created_at"] #=> some datetime instance
account.custom_data.has_key? "created_at"? #=> true
```

The only way that this could be fixed is if the custom_data resource was materialized on instantiation, and i would have to introduce a a new instance method to the data_store class and the base class.