Flatten a folded linked list in golang

Go program for Flatten a folded linked list. Here problem description and other solutions.

package main
import "fmt"
/*
  Go program for
  Unfold a folded linked list OR
  flatten folded linked list
*/
// Linked list node
type LinkNode struct {
	data int
	next * LinkNode
}
func getLinkNode(data int) * LinkNode {
	// return new LinkNode
	return &LinkNode {
		data,
		nil,
	}
}
type SingleLL struct {
	head * LinkNode
}
func getSingleLL() * SingleLL {
	// return new SingleLL
	return &SingleLL {
		nil,
	}
}
// Insert node at the beginning of linked list
func(this *SingleLL) addNode(data int) {
	// Create node
	var node * LinkNode = getLinkNode(data)
	node.next = this.head
	// Set new head
	this.head = node
}
// Display linked list element
func(this SingleLL) display() {
	if this.head == nil {
		return
	}
	var temp * LinkNode = this.head
	// iterating linked list elements
	for (temp != nil) {
		fmt.Print(" ", temp.data, " →")
		// Visit to next node
		temp = temp.next
	}
	fmt.Println(" NULL")
}
// This is handle the request of unfold given linked list nodes
func(this SingleLL) unfoldList() {
	if this.head == nil {
		fmt.Println("\n Empty linked list")
		return
	}
	var temp * LinkNode = this.head
	var auxiliary * LinkNode = nil
	var hold * LinkNode = nil
	// Loop which is separating the fold elements 
	for (temp.next != nil) {
		// Get the second element
		hold = temp.next
		if hold.next != nil {
			// When exists pair of three elements
			temp.next = hold.next
			// Visit to 3rd element
			temp = hold.next
		} else {
			// When get last two elements
			temp.next = nil
		}
		// Add new node at beginning of auxiliary linked list
		hold.next = auxiliary
		// Make new head node
		auxiliary = hold
	}
	if temp != nil {
		// Combine lists
		temp.next = auxiliary
	}
}
func main() {
	// Create a empty linked lists
	var sll1 * SingleLL = getSingleLL()
	var sll2 * SingleLL = getSingleLL()
	//  Constructed first linked list
	//  2 → 5 → 1 → 8 → 10 → 4 → 9 → 7 → NULL
	sll1.addNode(7)
	sll1.addNode(9)
	sll1.addNode(4)
	sll1.addNode(10)
	sll1.addNode(8)
	sll1.addNode(1)
	sll1.addNode(5)
	sll1.addNode(2)
	// Constructed second linked list
	// 1 → 2 → 3 → 4 → 5 → 6 → 7 → NULL
	sll2.addNode(7)
	sll2.addNode(6)
	sll2.addNode(5)
	sll2.addNode(4)
	sll2.addNode(3)
	sll2.addNode(2)
	sll2.addNode(1)
	// Test A
	fmt.Println(" Before unfold")
	sll1.display()
	sll1.unfoldList()
	fmt.Println(" After unfold")
	sll1.display()
	// Test B
	fmt.Println(" Before unfold")
	sll2.display()
	sll2.unfoldList()
	fmt.Println(" After unfold")
	sll2.display()
}

Output

 Before unfold
 2 → 5 → 1 → 8 → 10 → 4 → 9 → 7 → NULL
 After unfold
 2 → 1 → 10 → 9 → 7 → 4 → 8 → 5 → NULL
 Before unfold
 1 → 2 → 3 → 4 → 5 → 6 → 7 → NULL
 After unfold
 1 → 3 → 5 → 7 → 6 → 4 → 2 → NULL