def __call__(
        self,
        start: TLineNo,
        end: TLineNo,
        missing_cause_msg: str | None = None,
        action_msg: str | None = None,
    ) -> None:
        """
        Record an arc from `start` to `end`.

        `missing_cause_msg` is a description of the reason the arc wasn't
        taken if it wasn't taken.  For example, "the condition on line 10 was
        never true."

        `action_msg` is a description of what the arc does, like "jump to line
        10" or "exit from function 'fooey'."

        """

        Record an arc from `start` to `end`.

        `missing_cause_msg` is a description of the reason the arc wasn't
        taken if it wasn't taken.  For example, "the condition on line 10 was
        never true."

        `action_msg` is a description of what the arc does, like "jump to line
        10" or "exit from function 'fooey'."

        
coverage/parser.py