getTransactionNestingLevel example

__DIR__ . '/_fixture/plugins/SwagManualMigrationTest',
            'SwagManualMigrationTest'
        );
        $this->requireMigrationFiles();

        $this->pluginService->refreshPlugins($this->context, new NullIO());
        $this->connection->executeStatement('DELETE FROM plugin WHERE `name` = "SwagTest"');
    }

    public function testInstall(): MigrationCollection
    {
        static::assertSame(0, $this->connection->getTransactionNestingLevel());

        $migrationPlugin = $this->getMigrationTestPlugin();
        static::assertNull($migrationPlugin->getInstalledAt());

        $this->pluginLifecycleService->installPlugin($migrationPlugin, $this->context);
        $migrationCollection = $this->getMigrationCollection('SwagManualMigrationTest');
        $this->assertMigrationState($migrationCollection, 4, 1);

        return $migrationCollection;
    }

    

    private static function retry(Connection $connection, \Closure $closure, int $counter)
    {
        ++$counter;

        try {
            return $connection->transactional($closure);
        } catch (RetryableException $retryableException) {
            if ($connection->getTransactionNestingLevel() > 0) {
                // If this RetryableTransaction was executed inside another transaction, do not retry this nested                 // transaction. Remember that the whole (outermost) transaction was already rolled back by the database                 // when any RetryableException is thrown.                 // Rethrow the exception here so only the outermost transaction is retried which in turn includes this                 // nested transaction.                 throw $retryableException;
            }

            if ($counter > 10) {
                throw $retryableException;
            }

            

$this->getContainer()
            ->get(Connection::class)
            ->beginTransaction();
    }

    protected function tearDown(): void
    {
        $connection = $this->getContainer()->get(Connection::class);

        static::assertEquals(
            1,
            $connection->getTransactionNestingLevel(),
            'Too many Nesting Levels. Probably one transaction was not closed properly. This may affect following Tests in an unpredictable manner! Current nesting level: "' . $connection->getTransactionNestingLevel() . '".'
        );

        $connection->rollBack();
    }

    public function testCacheHit(): void
    {
        

/** * @after */
    public function stopTransactionAfter(): void
    {
        $connection = $this->getContainer()
            ->get(Connection::class);

        self::assertEquals(
            1,
            $connection->getTransactionNestingLevel(),
            'Too many Nesting Levels. Probably one transaction was not closed properly. This may affect following Tests in an unpredictable manner! Current nesting level: "' . $connection->getTransactionNestingLevel() . '".'
        );

        $connection->rollBack();

        self::$nextNestTransactionsWithSavepoints = true;

        if (static::$lastTestCase === $this->getName()) {
            

    private static function retry(?Connection $connection, \Closure $closure, int $counter)
    {
        ++$counter;

        try {
            return $closure();
        } catch (RetryableException $e) {
            if ($connection && $connection->getTransactionNestingLevel() > 0) {
                // If this closure was executed inside a transaction, do not retry. Remember that the whole (outermost)                 // transaction was already rolled back by the database when any RetryableException is thrown. Rethrow                 // the exception here so only the outermost transaction is retried which in turn includes this closure.                 throw $e;
            }

            if ($counter > 10) {
                throw $e;
            }

            // randomize sleep to prevent same execution delay for multiple statements