public function getById(Model $model, $id) {
        return $model->find('first', array(
            'conditions' => array($model->alias . '.' . $model->primaryKey => $id),
            'contain' => array_keys($model->belongsTo),
            'cache' => array($model->alias . '::getById', $id),
            'cacheExpires' => $this->getExpiration($model)
        ));
    }