code: public function getAsArray($fieldName)
      {
          if (!array_key_exists($fieldName, $this->row)) {
              return [];
          }
  
          $result = $this->row[$fieldName];
  
          if (empty($result)) {
              return [];
          }
  
          return (array)$result;
      }
docs: Get array from a single field
  
  @param string $fieldName
  @return array