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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_true_capacity(self):
 """Get the capacity for the scheduled activity, taking into account activity defaults and overrides."""


        c = self.capacity
        if c is not None:
            return c
        else:
            if self.rooms.count() == 0 and self.activity.default_capacity:
                # use activity-level override
                return self.activity.default_capacity

            rooms = self.get_true_rooms()
            return EighthRoom.total_capacity_of_rooms(rooms)