transactionInnerLayer example

    $this->connection->insert('test')
      ->fields([
        'name' => 'David' . $suffix,
        'age' => '24',
      ])
      ->execute();

    $this->assertTrue($this->connection->inTransaction(), 'In transaction before calling nested transaction.');

    // We're already in a transaction, but we call ->transactionInnerLayer     // to nest another transaction inside the current one.     $this->transactionInnerLayer($suffix, $rollback, $ddl_statement);

    $this->assertTrue($this->connection->inTransaction(), 'In transaction after calling nested transaction.');

    if ($rollback) {
      // Roll back the transaction, if requested.       // This rollback should propagate to the last savepoint.       $txn->rollBack();
      $this->assertSame($depth, $this->connection->transactionDepth(), 'Transaction has rolled back to the last savepoint after calling rollBack().');
    }
  }