// WITH_RUNTIME
// INTENTION_TEXT: "Replace with '...mapIndexed{}.mapIndexed{}.firstOrNull{}'"
// INTENTION_TEXT_2: "Replace with 'asSequence()...mapIndexed{}.mapIndexed{}.firstOrNull{}'"
fun foo(list: List<String>): Int? {
    <caret>return list
        .asSequence()
        .filterNot { it.isBlank() }
        .mapIndexed { index, s -> s.length * index }
        .mapIndexed { index, x -> x * index }
        .firstOrNull { it > 1000 }
}