public function deleteOldFileOnSave(EntityInterface $entity, $oldIdField = 'old_file_id') {
		if (!empty($entity->get($oldIdField)) && $entity->get('model')) {
			$oldEntity = $this->_table->find()
				->contain([])
				->where([
					$this->_table->getAlias() . '.' . $this->_table->getPrimaryKey() => $entity->get($oldIdField),
					'model' => $entity->get('model')
				])
				->first();

			if (!empty($oldEntity)) {
				return $this->_table->delete($oldEntity);
			}
		}

		return false;
	}