objectTest{sealedabstractclassExpr// Change type of `arg` to `Any` and the exhaustiveness warning// is issued belowcaseclassOp(arg:Expr)extendsExprcaseclassNotHandled(num:Double)extendsExprdefexhausto(expr:Expr):Unit=exprmatch{caseOp(Op(_))=>caseOp(_)=>}}