public function search($keyword, array $filters = [])
 {
     $query = ['index' => 'eshop', 'type' => 'product', 'body' => ['query' => ['term' => ['title' => $keyword]]]];
     // add limit
     if (isset($filters['limit'])) {
         $query['size'] = $filters['limit'];
         if (isset($filters['offset'])) {
             $query['from'] = $filters['offset'];
         }
     }
     $result = $this->es->search($query);
     $return = ['total' => $result['hits']['total'], 'products' => []];
     foreach ($result['hits']['hits'] as $product) {
         $return['products'][] = $product['_source'];
     }
     return $return;
 }