public static IUmbracoBuilder SetMediaFileSystem(
        this IUmbracoBuilder builder,
        Func<IServiceProvider, IFileSystem> filesystemFactory)
    {
        builder.Services.AddUnique(
            provider =>
            {
                IFileSystem filesystem = filesystemFactory(provider);

                // We need to use the Filesystems to create a shadow wrapper,
                // because shadow wrapper requires the IsScoped delegate from the FileSystems.
                // This is used by the scope provider when taking control of the filesystems.
                FileSystems fileSystems = provider.GetRequiredService<FileSystems>();
                IFileSystem shadow = fileSystems.CreateShadowWrapper(filesystem, "media");

                return provider.CreateInstance<MediaFileManager>(shadow);
            });
        return builder;
    }

IMediaService