Kotlin
fun execute(userId: Int?, targetId: Int?): String {
val userMap = createUserMap()
return userMap.entries
.stream()
.filter { entry ->
if (userMap.containsKey(userId)) {
[email protected]()
.stream()
.filter true
}
if (userMap.containsKey(targetId)) {
[email protected]()
.stream()
.filter true
}
false
}.map { entry -> entry.value }.toString()
}