import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
val list = listOf("abcd", "abc", "ab", "abcde")
val shortestString = list.minBy { it.length }
println(shortestString) // ab

val emptyList = emptyList<String>()
val emptyMin = emptyList.minBy { it.length }
println(emptyMin) // null
//sampleEnd
}