Unity DI VNext - Unity Registration

UnityDiVNextRegistration.cs

public static class UnityRegistration
{
    public static void Populate(this IUnityContainer container,
        IServiceCollection services)
    {
        container.AddExtension(new EnumerableResolutionExtension());

        container.RegisterInstance(services);
        container.RegisterType<IServiceProvider, UnityServiceProvider>();
        container.RegisterType<IServiceScopeFactory, UnityServiceScopeFactory>();

        foreach (var descriptor in services)
        {
            Register(container, descriptor);
        }
    }

    private static void Register(IUnityContainer container,
        ServiceDescriptor descriptor)
    {
        if (descriptor.ImplementationType != null)
        {
            container.RegisterType(descriptor.ServiceType,
                descriptor.ImplementationType,
                GetLifetimeManager(descriptor.Lifetime));

            container.RegisterType(descriptor.ServiceType,
                descriptor.ImplementationType,
                descriptor.ImplementationType.ToString(),
                GetLifetimeManager(descriptor.Lifetime));
        }
        else if (descriptor.ImplementationFactory != null)
        {
            container.RegisterType(descriptor.ServiceType,
                GetLifetimeManager(descriptor.Lifetime),
                new InjectionFactory(unity =>
                {
                    var provider = unity.Resolve<IServiceProvider>();
                    return descriptor.ImplementationFactory(provider);
                }));

            container.RegisterType(descriptor.ServiceType,
                Guid.NewGuid().ToString(),
                GetLifetimeManager(descriptor.Lifetime),
                new InjectionFactory(unity =>
                {
                    var provider = unity.Resolve<IServiceProvider>();
                    return descriptor.ImplementationFactory(provider);
                }));
        }
        else if (descriptor.ImplementationInstance != null)
        {
            container.RegisterInstance(descriptor.ServiceType,
                descriptor.ImplementationInstance,
                GetLifetimeManager(descriptor.Lifetime));

            container.RegisterInstance(descriptor.ServiceType,
                Guid.NewGuid().ToString(),
                descriptor.ImplementationInstance,
                GetLifetimeManager(descriptor.Lifetime));
        }
    }

    private static LifetimeManager GetLifetimeManager(ServiceLifetime lifecycle)
    {
        switch (lifecycle)
        {
            case ServiceLifetime.Transient:
                return new TransientLifetimeManager();
            case ServiceLifetime.Singleton:
                return new ContainerControlledLifetimeManager();
            case ServiceLifetime.Scoped:
                return new HierarchicalLifetimeManager();
        }

        return new TransientLifetimeManager();
    }
}