-test_paire.nit:45,7--10: Redef error: Pair is an imported class. Add the redef keyword to refine it.
-test_paire.nit:54,7--10: Redef error: Pair is an imported class. Add the redef keyword to refine it.
+test_paire.nit:45,27--39: Error: A formal parameter type `E' already exists
+test_paire.nit:54,20--25: Error: A formal parameter type `E' already exists