```scala scala> ((x => x): Function1[Int, Int] { def apply(arg: Int): Int }).apply(arg = 1) 1 |((x => x): Function1[Int, Int] { def apply(arg: Int): Int }).apply(arg = 1) | ^^^^^^^ | method apply: (v1: Int): Int does not have a parameter arg scala> ((x => x): Function1[Int, Int] { def apply(arg: Int): Int }).apply(v1 = 1) val res0: Int = 1 ``` this is different in scala 2