def add_value(self, value, jump=False, target=None):
        self.log.debug("Adding '%s' to the displayed value. Jump=%s", value,
                       jump)

        # As a starting point, we'll base our assumed current value of the reels
        # based on whatever the machine thinks they are. This is subject to
        # change, which is why we use our own variable here.
        current_reel_value = self.assumed_value_int

        if self.jump_in_progress:
            self.log.debug("There's a jump in progress, so we'll just change "
                           "the target of the jump to include our values.")
            # We'll base our desired value off whatever the reel is advancing
            # plus our value, because since there's a jump in progress we have
            # no idea where the reels are at this exact moment
            current_reel_value = self.reel_list_to_int(self.desired_value_list)
            jump = True

        if current_reel_value == - 999:
            self.log.debug("Current displayed value is unkown, "
                           "so we're jumping to the new value.")
            current_reel_value = 0
            jump = True

        # If we have a target, yay! (And thank you to whatever called this!!)
        # If not we have to use our current_reel_value as the baseline which is
        # fine, but it makes a lot of assumptions
        if target is None:
            target = current_reel_value + value

        elif value < 0:
            self.log.debug("add_value is negative, so we're subtracting this "
                           "value. We will do this via a jump.")
            jump = True

        # If we have to jump to this new value (for whatever reason), go for it
        if jump:
            self.set_value(target)

        # Otherwise we can do the cool step-wise advance
        else:
            self.desired_value_list = self.int_to_reel_list(target)
            self._step_advance_add_steps(value)
Adds value to a ScoreReelGroup.
dataset/ETHPy150Open missionpinball/mpf/mpf/devices/score_reel.py/ScoreReelGroup.add_value