/**
* Converts foreign ids to MongoIds, then
* gets the model with the given ID and options.
* @param String $id ID to match.
* @param [String => Mixed] $opts
* @return Model
*/
public function show($id, array $opts)
{
$opts['lrs_id'] = new \MongoId($opts['lrs_id']);
return parent::show($id, $opts);
}