product/Index可以实现重写:
'\fecshop\app\appfront\modules\Catalog\block\product\Index' => '\appfront\local\local_modules\Catalog\block\product\Index',
但是重写product\CustomOption类就重写不了:
'\fecshop\app\appfront\modules\Catalog\block\product\CustomOption' => '\appfront\local\local_modules\Catalog\block\product\CustomOption',