public function getSelectedCombinationFromSession($productId)
    {
        $combination = null;

        if (!empty($productId)) {
            $items = Yii::$app->session[self::SESSION_KEY_SELECTED_COMBINATIONS];

            if (!empty($items)) {
                $combinationId = null;

                foreach ($items as $item) {
                    if ($item['productId'] == $productId) {
                        $combinationId = $item['combinationId'];
                    }
                }

                $combination = Combination::findOne($combinationId);
            }
        }

        return $combination;
    }