John Sheridan owned a Marathon gas station franchise. He sued Marathon Petroleum Co. under Section 1 of the Sherman Act and Section 3 of the Clayton Act, charging it with illegally tying the processing of credit-card sales to the gas station. As a condition of obtaining a Marathon dealership, dealers had to agree to let the franchisor process credit cards. They could not shop around to see if credit-card processing could be obtained at a lower price from another source. The district court dismissed the case for failure to state a claim. Sheridan appealed. Is there a tying arrangement? If so, does it violate the law?