getPasswordUpgrader example

$user = $passport->getUser();
        if (!$user instanceof PasswordAuthenticatedUserInterface || null === $user->getPassword()) {
            return;
        }

        $passwordHasher = $this->hasherFactory->getPasswordHasher($user);
        if (!$passwordHasher->needsRehash($user->getPassword())) {
            return;
        }

        $passwordUpgrader = $badge->getPasswordUpgrader();

        if (null === $passwordUpgrader) {
            if (!$passport->hasBadge(UserBadge::class)) {
                return;
            }

            /** @var UserBadge $userBadge */
            $userBadge = $passport->getBadge(UserBadge::class);
            $userLoader = $userBadge->getUserLoader();
            if (\is_array($userLoader) && $userLoader[0] instanceof PasswordUpgraderInterface) {
                $passwordUpgrader = $userLoader[0];
            }