Implementation of treeMapOf and toTreeMap equivalent to mapOf and toMap in kotlin.

TreeMapsInKotlin.kt

import java.util.TreeMap

fun <K, V> treeMapOf(vararg pairs: Pair<K, V>): TreeMap<K, V> =
    TreeMap<K, V>().apply { putAll(pairs) }

fun <K : Comparable<K>, V> Map<K, V>.toTreeMap(): TreeMap<K, V> =
    TreeMap<K, V>().apply { putAll(this@toTreeMap) }

 // Usage:
 val mapA = treeMapOf(1 to "A")
 val mapB = mapOf(1 to "A").toTreeMap()