the second start
split three view part
extract shopping_inventory
extract free_inventory
merge shopping_inventory and free_inventory to shopping_inventory
get_shopping_inventory
extract get_free_goods_inventory function
extract get_summary_inventory and get_total_cost and get_total_free function
change shopping_list to expected_shopping_list
change expected_shopping_list and extracted get_goods_information function
extract count_goods_cost_in_shopping_list
extract count_free_goods_number function
extract get_shopping_list function
realize get_shopping_list function