A unique hiring problem using hashet

UniqueHiring.kt

fun main(vararg args: String) {
    val nameSet: HashSet<String> = getUniqueListOfNames(listOf("Ahmed", "Ahmed", "Hassan", "Omar"))

    println(validateHiring(nameSet, "Hamada"))
}

fun validateHiring(nameSet: HashSet<String>, searchingName: String): Boolean = !nameSet.contains(searchingName)

fun getUniqueListOfNames(listOfFullNames: List<String>): HashSet<String> {
    val nameSet = HashSet<String>()
    listOfFullNames.forEach { currentName -> nameSet.add(currentName) }

    return nameSet
}