def rename_file(self, old_save_name, new_save_name, new_path):
        """This only updates the name and path we use to track the file's size
        and upload progress. Doesn't rename it on the back end or make us
        upload from anywhere else.
        """
        if old_save_name in self._files:
            del self._files[old_save_name]
        self.update_file(new_save_name, new_path)
This only updates the name and path we use to track the file's size
        and upload progress. Doesn't rename it on the back end or make us
        upload from anywhere else.