## Minimized code ```Scala class X object X { extension (x: List[X]) { def isNull = x.head == null } } @main def test = List(null: X).isNull ``` https://scastie.scala-lang.org/He9Pm96ySZCBCziHLktlXg ## Output Error: ```scala Found: X Required: Any* ``` ## Expectation Should compile. If a _redundant_ second set of parentheses is added in `List((null: X))`, then the example compiles: ```scala class X object X { extension (x: List[X]) { def isNull = x.head == null } } @main def test = List((null: X)).isNull ``` https://scastie.scala-lang.org/dwFH7NAsQyqKpoXHuzAWiA