import java.util.*

fun use() {
    val x: String? = "x"
    Optional.of(x)
        // SUCCESS
        // ORIGINAL:    fun <T : Any!> of(T & Any): Optional<T & Any> defined in java.util.Optional
        // SUBSTITUTED: fun <T : Any!> of(String): Optional<String> defined in java.util.Optional

    Optional.of(x!!)
        // SUCCESS
        // ORIGINAL:    fun <T : Any!> of(T & Any): Optional<T & Any> defined in java.util.Optional
        // SUBSTITUTED: fun <T : Any!> of(String): Optional<String> defined in java.util.Optional
    Optional.ofNullable(x)
        // SUCCESS
        // ORIGINAL:    fun <T : Any!> ofNullable(T?): Optional<T & Any> defined in java.util.Optional
        // SUBSTITUTED: fun <T : Any!> ofNullable(String?): Optional<String> defined in java.util.Optional
}