How can i surcharge a connection configuration from a controller in Lithium?

Question

I'm building a GooglePlaces API, it is package as an http datasource.

I thought it would be a good idea to ship it with a basic Places model & a basic gplaces connection so that the datasource could be used out of the box in my app PlacesController using :

use app\models\Places;
use google\models\Places as GPlaces;

class PlacesController extends \lithium\action\Controller { ... }

But i'd like to be able to somehow surcharge the plugin default connection gplaces with so API key.

Tried :

GPlaces::config(array(
    'key' => '<private_api_key>'
));

But it does not affect (as we could expect) the Connection,

Any ideas ?