public static IOrchardFileSystem GetExtensionFileProvider(
            this IOrchardFileSystem parentFileSystem,
            ExtensionDescriptor extensionDescriptor,
            ILogger logger)
        {
            var subPath = parentFileSystem.Combine(extensionDescriptor.Location, extensionDescriptor.Id);

            return(parentFileSystem
                   .GetSubPathFileProvider(subPath, logger));
        }