@classmethod<EOL><INDENT>def add_product_flag(cls, condition=conditions.FlagBase.ENABLE_IF_TRUE):<DEDENT>
flag = conditions.ProductFlag.objects.create(<EOL>description="<STR_LIT>",<EOL>condition=condition,<EOL>)<EOL>flag.products.add(cls.PROD_1)<EOL>flag.enabling_products.add(cls.PROD_2)<EOL>
Adds a product flag condition: adding PROD_1 to a cart is
        predicated on adding PROD_2 beforehand.