public function beforeDelete(Delete $event)
    {
        $pmkVal = $event->primaryKey;
        $entFrk = $this->getForeignKey();
        Sql::createSql($this->getEntity()->getAdapter())
            ->delete($this->getRelationTable())
            ->where(
                [
                    "{$entFrk} = :id" => [
                        ":id" => $pmkVal
                    ]
                ]
            )
            ->execute();
    }