Chris Sagers, the James A. Thomas Professor of Law, appeared at Villanova University School of Law last week to give a presentation on his forthcoming book “Apple, Antitrust, and Irony,” as part of the school’s visiting scholar series.The book concerns the Justice Department’s 2012 antitrust challenge to an agreement among the Apple computer company and several publishing firms to fix the prices of electronic books. It will be published this fall by Harvard University Press.