.NET: Package Part with ExtraData/Metadata?

Im using .NET Package and would like to store some extra data/metadata for each PackagePart. For now Im having a "shadow" file for each file. For myfile1.dat there is a myfile.dat.meta. In for instance SharpZipLib it is possible to add ExtraData (byte[]) for each ZipEntry but for some reasons I开发者_如何学JAVA have choosen Package for this project. Is it possible somehow to add this functionality to (Zip)Package? I would like to be able to attach metadata to each PackagePart without using "shadow"-files. Is it possible to use ADS (Alternate Data Stream) for a ZipPackage? Any other options?