Demo.kt

class Demo {
    fun doSth(){
        val array = arrayOf(0,0,0,0,0,0,0)
        val collection : Collection = TreeCollection(array)
        (collection as TreeCollection).addToTree(1)
        (collection as TreeCollection).addToTree(2)
        (collection as TreeCollection).addToTree(3)
        (collection as TreeCollection).addToTree(4)
        (collection as TreeCollection).addToTree(5)
        (collection as TreeCollection).addToTree(6)
        (collection as TreeCollection).addToTree(7)
        val iterator = collection.createIterator()
        while (iterator.hasNext())
            iterator.next()
    }
}