docs: def format_exception(self):
          """
          Return the same data as from traceback.format_exception.
          """
          import traceback
          frames = self.get_traceback_frames()
          tb = [(f['filename'], f['lineno'], f['function'], f['context_line']) for f in frames]
          list = ['Traceback (most recent call last):\n']
          list += traceback.format_list(tb)
          list += traceback.format_exception_only(self.exc_type, self.exc_value)
          return list