Champagne and pork dumplings pleased celebrants tonight at Lee Wah Heen on Chestnut Street. But it was a bittersweet moment for those who used to patronize this restaurant’s sister establishment Lai Toh Heen at Mt Pleasant Rd. and Soudan Ave. As we told you in October, Lai Toh Heen has closed. It has not been clear why until now. The management decided that business conditions did not merit renewal of the lease. In other words, insufficient business.