Lazy load folder and file meta

This works for me but YMMV so please advise and let me know how can I improve this.

Say you want to list items in root folder:

    client.root_folder.items

This launches two calls to Box API:

* call to fetch root folder meta,
* call to fetch root folder items.

For this particular case all I need is just items and with lazy loading I can skip one API call for root folder and just fetch root folder items directly.