List the business ID of shopping business that have 4 stars ratings.
shopping business refers to category_name = 'Shopping'; 4 stars ratings refers to stars = 4
SELECT T1.business_id FROM Business AS T1 INNER JOIN Business_Categories AS T2 ON T1.business_id = T2.business_id INNER JOIN Categories AS T3 ON T2.category_id = T3.category_id WHERE T3.category_name = 'Shopping' AND T1.stars = 4