def __init__(self, center, half_width, half_height):
        self.center = center
        self.rx = half_width
        self.ry = half_height
Return an identity-map key for use in storing/retrieving an
dataset/ETHPy150Open los-cocos/cocos/cocos/collision_model.py/AARectShape.__init__--crossover with--dataset/ETHPy150Open goFrendiAsgard/kokoropy/kokoropy/packages/sqlalchemy/orm/mapper.py/Mapper.identity_key_from_row