Effectively insert node at beginning of circular linked list in kotlin

Kotlin program for Effectively insert node at beginning of circular linked list . Here problem description and explanation.

// Kotlin Program 
// Insert node at beginning of circular linked list
// Using head and tail nodes

// Define class of linked list Node
class LinkNode
{
	var data: Int;
	var next: LinkNode ? ;
	constructor(data: Int, first: LinkNode ? )
	{
		// Set node value
		this.data = data;
		this.next = first;
	}
}
class CircularLinkedList
{
	var head: LinkNode ? ;
	var tail: LinkNode ? ;
	constructor()
	{
		this.head = null;
		this.tail = null;
	}
	// Insert node at begining of circular linked list
	fun insert(value: Int): Unit
	{
		// Create a node
		val node: LinkNode = LinkNode(value, this.head);
		if (this.tail == null)
		{
			// First node of linked list
			this.tail = node;
		}
		// Make new head
		this.head = node;
		// Connecting the last node to the top of the next field
		this.tail?.next = this.head;
	}
	// Display node element of circular linked list
	fun display(): Unit
	{
		if (this.head == null)
		{
			println("Empty Linked List");
		}
		else
		{
			print("Linked List Element :");
			var temp: LinkNode ? = this.head;
			// iterate linked list
			while (temp != null)
			{
				// Display node
				print("  " + temp.data);
				if (temp == this.tail)
				{
					// Stop iteration
					// Or break;
					return;
				}
				// Visit to next node
				temp = temp.next;
			}
		}
	}
}
fun main(args: Array < String > ): Unit
{
	val task: CircularLinkedList = CircularLinkedList();
	// Add following linked list nodes
	task.insert(8);
	task.insert(7);
	task.insert(6);
	task.insert(5);
	task.insert(4);
	task.insert(3);
	task.insert(2);
	task.insert(1);
	// Display node
	task.display();
}

Output

Linked List Element :  1  2  3  4  5  6  7  8