// WITH_RUNTIME
// INTENTION_TEXT: "Replace with '+= flatMap{}.takeWhile{}'"
// INTENTION_TEXT_2: "Replace with '+= asSequence().flatMap{}.takeWhile{}'"
fun foo(list: List<String>, target: MutableCollection<Int>) {
    <caret>target += list
        .flatMap { it.indices }
        .takeWhile { it <= 1000 }
}