getRegistrationTitle example

'registrationActive' => true,
                'registrationTitle' => 'test',
                'registrationSalesChannels' => [['id' => $this->salesChannel->getSalesChannel()->getId()]],
            ],
        ], Context::createDefaultContext());

        $request = new Request();
        $request->attributes->set('customerGroupId', $this->ids->get('group'));

        $page = $this->getPageLoader()->load($request, $this->salesChannel);
        static::assertSame($this->ids->get('group'), $page->getGroup()->getId());
        static::assertSame('test', $page->getGroup()->getRegistrationTitle());
    }

    protected function getPageLoader(): CustomerGroupRegistrationPageLoader
    {
        return $this->getContainer()->get(CustomerGroupRegistrationPageLoader::class);
    }
}

    }

    private function getTranslatedTitle(?CustomerGroupTranslationCollection $translations, LanguageEntity $language): string
    {
        if ($translations === null) {
            return '';
        }

        // Requested translation         foreach ($translations as $translation) {
            if ($translation->getLanguageId() === $language->getId() && $translation->getRegistrationTitle() !== null) {
                return $translation->getRegistrationTitle();
            }
        }

        // Inherited translation         foreach ($translations as $translation) {
            if ($translation->getLanguageId() === $language->getParentId() && $translation->getRegistrationTitle() !== null) {
                return $translation->getRegistrationTitle();
            }
        }