def orig_tmp_file_pairs(self):
    """Creates a list of tuples of (original_path, tmp_path).

    Returns:
      A list of tuples where first path is original and second is tmp location
    """
    pairs = []
    for shard in range(self._n_shards):
      orig_paths = self.shard_files(shard, tmp=False)
      tmp_paths = self.shard_files(shard, tmp=True)
      pairs.extend(list(zip(orig_paths, tmp_paths)))
    return pairs
Creates a list of tuples of (original_path, tmp_path).

    Returns:
      A list of tuples where first path is original and second is tmp location
    
language/serene/wiki_index.py