pause download from appstore and shutdown then resume after restarting computer I am using mountain lion on macbook pro.

I want to know if it is posible to pause while downloading xcode from appstore and shutdown my computer, then resume my download from where i paused it when I start my computer again. I need to know this because xcode is very large to download and due to slow internet speed I cannot download it all at once.
I've had mixed results with pausing app store download.
There is a decent chance it would start over from the beginning of downloading.