// WITH_STDLIB // SKIP_TXT fun InputWrapper.doMapping( foo: (From) -> List, bar: (List) -> Boolean = { it.isNotEmpty() }, ) = InputWrapper(value = foo(value)) data class InputWrapper(val value: TItem) data class Output(val source: InputWrapper>) fun main2(input: InputWrapper): Output { val output = input.doMapping( foo = { buildList { add("this is List") } }, bar = { it.isNotEmpty() }, ) return Output(source = output) }