Has the time come to federalize private competition law? The autonomous concept of undertaking in the CJEU's ruling in Case C-724/17 Vantaa v. Skanska Case C-724/17 Vantaan kaupunki v. Skanska Industrial Solutions Oy and Others , EU:C:2019:204 - Nagy Csongor István (MAASTRICHT JOURNAL OF EUROPEAN AND COMPARATIVE LAW, 2019)