'Verify save isn\'t overwriting any temporary files.
:param set save_files: Set of files about to be saved.
:raises certbot.errors.ReverterError:
when save is attempting to overwrite a temporary file.'

def _check_tempfile_saves(self, save_files):

    protected_files = []
    temp_path = os.path.join(self.config.temp_checkpoint_dir, 'FILEPATHS')
    if os.path.isfile(temp_path):
        with open(temp_path, 'r') as protected_fd:
            protected_files.extend(protected_fd.read().splitlines())
    new_path = os.path.join(self.config.temp_checkpoint_dir, 'NEW_FILES')
    if os.path.isfile(new_path):
        with open(new_path, 'r') as protected_fd:
            protected_files.extend(protected_fd.read().splitlines())
    for filename in protected_files:
        if (filename in save_files):
            raise errors.ReverterError(('Attempting    to    overwrite    challenge    file    -    %s' % filename))
