code: public Path.Root getPackageRoot(String name, SemanticVersion version) throws IOException {
  		Path.ID path = Trie.ROOT.append(name).append(version.toString());
  		return root.createRelativeRoot(path);
  	}
docs: Determine the package root. This is relative to the registry root and
  determines where the package will be stored. By default, this is given by
  the path <code>name/version/</code>.
  
  @return
  @throws IOException