def update(self, deadline: float) -> None:
        """Set deadline to absolute value.

        deadline argument points on the time in the same clock system
        as loop.time().

        If new deadline is in the past the timeout is raised immediatelly.

        Please note: it is not POSIX time but a time with
        undefined starting base, e.g. the time of the system power on.
        """
        if self._state == _State.EXIT:
            raise RuntimeError("cannot reschedule after exit from context manager")
        if self._state == _State.TIMEOUT:
            raise RuntimeError("cannot reschedule expired timeout")
        if self._timeout_handler is not None:
            self._timeout_handler.cancel()
        self._deadline = deadline
        if self._state != _State.INIT:
            self._reschedule()
Set deadline to absolute value.

        deadline argument points on the time in the same clock system
        as loop.time().

        If new deadline is in the past the timeout is raised immediatelly.

        Please note: it is not POSIX time but a time with
        undefined starting base, e.g. the time of the system power on.
        
lib/async_timeout/__init__.py