180         for subpath in self.new_metadata.iter_subpaths(path):
181             if self._get_old_tag(path, subpath) is None:
182                 yield subpath
194             for subpath in self.old_metadata.iter_subpaths(path):
195                 if self.new_metadata.get_tag(path, subpath) is None:
196                     yield subpath
208         for subpath in self.new_metadata.iter_subpaths(path):
209             old_tag = self._get_old_tag(path, subpath)
210             new_tag = self.new_metadata.get_tag(path, subpath)
212                 yield subpath
263     def _get_old_tag(self, path, subpath=None):  argument
264         return self.old_metadata and self.old_metadata.get_tag(path, subpath)        
354     def get_tag(self, path, subpath=None):  argument
356         ret = self._get_entry(path, subpath)
380     def _get_entry(self, path, subpath=None):  argument
389         return self._file_map.get((path, subpath))