John and Andrew Doney invented a device for balancingrotors. Although they registered their inventionwith the U.S. Patent and Trademark Office, itwas never put on the market as an automobile wheelbalancer. Some time later, Exetron Corp. producedan automobile wheel balancer that used a device similarto that of the Doneys. Given the fact that theDoneys had not put the patented product in commerce,does Exetron’s use of a similar device infringeon the Doneys’ patent? Explain your answer.