public function dropSchema(array $classes)
    {
        $dropSchemaSql = $this->getDropSchemaSQL($classes);
        $conn          = $this->em->getConnection();

        foreach ($dropSchemaSql as $sql) {
            try {
                $conn->executeQuery($sql);
            } catch (Throwable $e) {
                // ignored
            }
        }
    }