def _finish_action_msg(self, action_msg: str | None, end: TLineNo) -> str:
        """Apply some defaulting and formatting to an arc's description."""
        if action_msg is None:
            if end < 0:
                action_msg = "jump to the function exit"
            else:
                action_msg = "jump to line {lineno}"
        action_msg = action_msg.format(lineno=end)
        return action_msg
Apply some defaulting and formatting to an arc's description.
coverage/parser.py