How to de-duplicate a list of strings

deduplicate-case-insensitive.kt

class X {
    private val obst = listOf("Apple", "Pear", "Pear", "PEAR", "APPLE", "APRICOT", "Apple")

    @Test
    fun deduplicateCaseInsensitively_1() {
        val deduplicated = obst.asSequence().sortedWith(String.CASE_INSENSITIVE_ORDER).fold(ArrayList<String>(obst.size)) { a, o ->
            if (a.isEmpty() || !a.last().equals(o, true)) a += o
            a
        }
        println(deduplicated)
    }

    @Test
    fun deduplicateCaseInsensitively_2() {
        val deduplicated = obst.asSequence().toSortedSet(String.CASE_INSENSITIVE_ORDER)
        println(deduplicated)
    }    
}