class AthleticShoes_ColorBase extends Shoes_Base {};
class AthleticShoes_Blue extends AthleticShoes_ColorBase {};
class AthleticShoes_Black extends AthleticShoes_ColorBase {};
class AthleticShoes_Brown extends AthleticShoes_ColorBase {};
class AthleticShoes_Green extends AthleticShoes_ColorBase {};
class AthleticShoes_Grey extends AthleticShoes_ColorBase {};