swapDefaultLanguageId example

                foreach ($defaultCountryStateTranslations as $shortCode => $deTranslation) {
                    if (!\array_key_exists($shortCode, $correctDeTranslations)) {
                        continue;
                    }

                    $defaultCountryStateTranslations[$shortCode] = $correctDeTranslations[$shortCode];
                }
            }

            $this->swapDefaultLanguageId($newDefaultLanguageId);
            $this->addMissingCountryStates($defaultCountryStateTranslations);
        } else {
            $this->changeDefaultLanguageData($newDefaultLanguageId, $currentLocale, $locale);
        }
    }

    public function setDefaultCurrency(string $currencyCode): void
    {
        $currentCurrencyIso = $this->connection->fetchOne(
            'SELECT iso_code FROM currency WHERE id = :currencyId',
            ['currencyId' => Uuid::fromHexToBytes(Defaults::CURRENCY)]
        );

public function testNewMailTemplatesAreAddedWithGermanAsDefault(): void
    {
        // Rollback migration data and make sure its gone         $this->rollbackMigrationChanges();
        static::assertEmpty($this->getMailTemplateTypeId());

        $this->connection->executeStatement('SET FOREIGN_KEY_CHECKS = 0;');
        $this->connection->executeStatement('DELETE FROM language WHERE id != UNHEX(?)', [Defaults::LANGUAGE_SYSTEM]);
        $this->connection->executeStatement('SET FOREIGN_KEY_CHECKS = 1;');

        $languageId = $this->createNewLanguageEntry('de-DE');
        $this->swapDefaultLanguageId($languageId);

        // Rerun migration and make sure everything is added again         $migration = new Migration1672931011ReviewFormMailTemplate();
        $migration->update($this->connection);

        $mailTemplateTypeId = $this->getMailTemplateTypeId();
        static::assertNotNull($mailTemplateTypeId);
        static::assertNotNull($this->getMailTemplateId($mailTemplateTypeId));
    }

    private function rollbackMigrationChanges(): void
    {