protected function initializeConnection()
    {
        if (!$this->entityManager instanceof EntityManager) {
            $this->outputLine('This command only supports database connections provided by the Doctrine ORM Entity Manager.
				However, the current entity manager is an instance of %s.', [get_class($this->entityManager)]);
            $this->quit(1);
        }

        $this->dbalConnection = $this->entityManager->getConnection();
    }