createMailTypes example

class Migration1596441551CustomerGroupRegistration extends MigrationStep
{
    public function getCreationTimestamp(): int
    {
        return 1596441551;
    }

    public function update(Connection $connection): void
    {
        $this->updateCustomerTable($connection);
        $this->createTables($connection);
        $this->createMailTypes($connection);
    }

    public function updateDestructive(Connection $connection): void
    {
    }

    public function createMailTypes(Connection $connection): void
    {
        $enLangId = $this->fetchLanguageId('en-GB', $connection);
        $deLangId = $this->fetchLanguageId('de-DE', $connection);