public function delete(EntityInterface $entity)
 {
     $primaryKey = $this->getPrimaryKey();
     $data = $this->hydrator->extract($entity);
     if (isset($data[$primaryKey]) && $data[$primaryKey] > 0) {
         $this->db->delete()->from('main_table', $this->getMainTable())->where('main_table.' . $primaryKey . '=?', $data[$primaryKey])->run();
         return true;
     }
     return false;
 }