public function down(Schema $schema)
{
$this->abortIf($this->connection->getDatabasePlatform()->getName() != "postgresql");
$this->addSql("ALTER TABLE typo3_media_domain_model_imagevariant ALTER originalasset DROP NOT NULL");
$this->addSql("ALTER TABLE typo3_media_domain_model_thumbnail ALTER originalasset DROP NOT NULL");
$this->addSql("ALTER TABLE typo3_media_domain_model_thumbnail ALTER resource DROP NOT NULL");
}