Arch Technologies, Inc. is incorporated in Oregon, with its principal place of business in California. It sues Sullivan Castings Corporation (incorporated in Delaware with its principal place of business in Oregon) in federal court under a federal statute barring deceptive commercial practices in interstate commerce. It claims losses of $500,000. It also claims that Sullivan's conduct constitutes an unfair business practice under an Oregon statute, and seeks punitive damages on the state law claim. Oregon courts have never decided whether punitive damages may be awarded under its business practices statute. The federal judge wants to decline jurisdiction over the unfair business practices claim, since the governing law is unclear and the Oregon courts can provide a "surer footed" reading of the statute. What should the judge do?