Why cant i return the full $bean

I want to return the full bean object after save but,  if I try to get the whole bean nothing gets returned in my api

The code below saved a bean and I can get the bean ID but I also want to return the full bean

        $fkeyBean = BeanFactory::newBean("holo_FeatureKey");
        $fkeyBean->name                                     = $args['name'];
        $fkeyBean->status                                   = $args['status'];
        $fkeyBean->holokotetype                             = $args['type'];
        $fkeyBean->description                              = $args['description'];
        $fkeyBean->holo_featurekey_contactscontacts_ida     = $contact_id;
        $fkeyBean->accounts_holo_featurekey_1accounts_ida   = $account_id; 
        $fkeyBean->accounts_holo_featurekey_2accounts_ida   = $account_id; 
        $fkeyBean->uuid_c                                   = $args['uuid'];
        $fkeyBean->end_user_or_dealer_c                     = $args['enduser'];
        $fkeyBean->google_uuid_c                            = $args['google_uuid']; 
        $fkeyBean->google_drive_url_c                       = $args['google'];
        $fkeyBean->ponumber                                 = $args['ponumber'];
        $fkeyBean->save();

        if ($fkeyBean->load_relationship('s_serialnumber_holo_featurekey_1')) {
            $fkeyBean->s_serialnumber_holo_featurekey_1->add($serial_id);
        }

        if (isset($fkeyBean->id) && !empty($fkeyBean->id)) {
            $result['success']          = true;
            $result['fkey_id']          = $fkeyBean->id;
            $result['fkey']             = $fkeyBean;
            return $result;
        } 

Line 23 

$result['fkey'] = $fkeyBean;
this breaks the code but I don;'t get any error in the sugar log. If i comment out this line then i get the ID so why cant i return the whole object