public static IMultiFileSystemChangeFilter ToMultiFileSystemChangeFilter(this IEnumerable<SyncFolder> syncFolders, IChangeFilterFactory filterFactory)
{
var tuples = from syncFolder in syncFolders
let filter = filterFactory.GetFilter(syncFolder.Filter)
select new Tuple<string, IChangeFilter>(syncFolder.Name, filter);
return new MultiFileSystemChangeFilter(tuples);
}