code: def make_tokens(parse_buffer):
      
      tokens = []
      for token_type, result in parse_buffer:
          token = token_type(result)
          if token is not None:
              tokens.append(token)
      return tokens
docs: Takes a list of pairs (token_type, read_result) and
      applies token_type(read_result).
  
      Footnotes are already parsed before this point,
      and span-level parsing is started here.