public static function generateCacheKey($models, $postfix = 'properties')
    {
        $ids = ArrayHelper::getColumn($models, 'id', false);
        sort($ids);
        /** @var \yii\db\ActiveRecord $first */
        $first = reset($models);
        return $first::tableName() . ':' . implode(',', $ids) . "-$postfix";
    }