Parent mapping throws exception

Thanks for the api, I'm eager to use it!

Databases attached to workspaces returns following part for parent mapping. Since id is set by using `type` property, `json[json["type"]]`  returns `true` and fail to cast string. 

Here is sample from response:

``` 
 "parent": {
    "type": "workspace",
    "workspace": true
 }
```
