Nate, a businessperson, is a friend of Becky, the owner of a Fresh Coffee & Baked Goods store. Every day, Nate spends five minutes in Becky's store, looking at the goods and usually buying one or two cinnamon buns or bagels. One afternoon, Nate goes into the store, looks at the items, and picks up a $1 chocolate brownie. Nate waves the brownie at Becky without saying a word and walks out. Is there a contract? If so, how would it be classified in terms of formation, performance, and enforceability?