import kotlin.test.*

fun main(args: Array<String>) {
//sampleStart
val nullSequence: Sequence<Int>? = null
println(nullSequence.orEmpty().toList()) // []

val sequence: Sequence<Int>? = sequenceOf(1, 2, 3)
println(sequence.orEmpty().toList()) // [1, 2, 3]
//sampleEnd
}