public function admit($identifier, $password)
    {
        $user = $this->repository->getByIdentifier($identifier);
        
        if ($user instanceof UserInterface && $this->hasher->verify($password, $user->getPasswordHash())) {
            $this->admitUser($user);
            return true;
        } else if (is_object($user) && !$user instanceof UserInterface) {
            throw new \RuntimeException('Your users must implement "Laasti\Warden\Users\UserInterface".');
        }

        return false;
    }