Added 'get_amount_by_packages' method to Product class
Added 'get_amount_by_packages' method to Product class

baffolobill/django-lfs,wisonwang/django-lfs,leadbrick/django-lfs,wisonwang/django-lfs,baffolobill/django-lfs,baffolobill/django-lfs,diefenbach/django-lfs,diefenbach/django-lfs,pigletto/django-lfs,leadbrick/django-lfs,pigletto/django-lfs,diefenbach/django-lfs,leadbrick/django-lfs,pigletto/django-lfs,wisonwang/django-lfs