/**
  * @param null $valueField
  * @param null $labelField
  * @param array $additional
  * @return array
  */
 public function toOptionArray($valueField = null, $labelField = null, $additional = [])
 {
     if ($valueField === null) {
         $valueField = $this->searchResult->getIdFieldName();
     }
     if ($labelField === null) {
         $labelField = 'name';
     }
     $result = [];
     $additional['value'] = $valueField;
     $additional['label'] = $labelField;
     foreach ($this->searchResult->getItems() as $item) {
         $data = [];
         foreach ($additional as $code => $field) {
             $data[$code] = $item->getData($field);
         }
         $result[] = $data;
     }
     return $result;
 }