public function userRegistrationDatabase(String $email, String $keyRockId): object
{
    $entityManager = $this->getDoctrine()->getManager("gui");
    $user = new User();
    $user->setUserName($email);
    $user->setEmail($email);
    $user->setEnabled(true);
    $userRole = ['ROLE_USER','ROLE_ADMIN'];
    $user->addRole(implode(",",$userRole));
    $user->setKeyrockId($keyRockId);
    $entityManager->persist($user);
    $entityManager->flush();

    return $user;
}

public function testUserRegistrationDatabase()
{
    $userManager = self::$kernel->getContainer()
        ->get('test.'. UserManagement::class);
    $mail = 'notexistinguser@mail.com';
    $keyRockId = '45091fd63a1';

    $user = $userManager->userRegistrationDatabase($mail,$keyRockId);

}

self::$kernel->getContainer()
        ->get('doctrine')
        ->getManager('test_gui');