docs: def traceback_string():
      """
      Helper function that formats most recent traceback.  Useful when a program has an overall try/except
      and it wants to output the program trace to the log.
      :return: formatted traceback string (or None if no traceback available)
      """
      tb_string = None
      exc_type, exc_value, exc_traceback = traceback.sys.exc_info()
      if exc_type is not None:
          display_lines_list = [str(exc_value)] + traceback.format_tb(exc_traceback)
          tb_string = "\n".join(display_lines_list)
      return tb_string