def __remove_obsolete_metadata(self):
clean = {}<EOL>for key, _ in self._source_file_names.items():<EOL><INDENT>if key in self._pystratum_metadata:<EOL><INDENT>clean[key] = self._pystratum_metadata[key]<EOL><DEDENT><DEDENT>self._pystratum_metadata = clean<EOL>
Removes obsolete entries from the metadata of all stored routines.