Shirley (owner of shirley's scuba, inc.) is a popular manufacturer of scuba gear. before she allows a store to carry her line of scuba gear, she requires that the store owner agree that her line is the only line of scuba gear the store will carry. she also requires that if a store carries her line of scuba gear, it must carry her line of wet suits. sales of other manufacturer's gear and wet suits have begun a steady decline. she is accused of violating antitrust laws. shirley, however, replies that she is simply conducting good business practices. the agreements between shirley and sellers to the effect that the stores must carry shirley's line of wet suits are