A final class can't be proxied

[videni]

[ProxyManager\Exception\InvalidProxiedClassException] Provided class "Sylius\Bundle\CoreBundle\OAuth\UserProvider" is final and cannot be proxied

 <service id="sylius.oauth.user_provider" class="Sylius\Bundle\CoreBundle\OAuth\UserProvider" lazy="true">
            <argument type="string" id="%sylius.model.admin_user.class%" />
            <argument type="service" id="sylius.factory.customer" />
            <argument type="service" id="sylius.factory.admin_user" />
            <argument type="service" id="sylius.repository.admin_user" />
            <argument type="service" id="sylius.factory.admin_oauth_user" />
            <argument type="service" id="sylius.repository.admin_oauth_user" />
            <argument type="service" id="sylius.manager.admin_user" />
            <argument type="service" id="sylius.canonicalizer" />
        </service>

Interesting , this exception doesn't happen in Sylius full installation , but it happens in my customization, I found that lots of class are defined as final, after I update to the latest commit, as the exception shows a final class can't be proxied , how does Sylius bypass this trouble?