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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 in_attack_range_of(self, unit: Unit, bonus_distance: Union[int, float] = 0) -> "Units": """ Filters units that are in attack range of the unit in parameter """

        return self.filter(lambda x: unit.target_in_range(x, bonus_distance=bonus_distance))