Check for continuous binary tree in golang

Go program for Check for continuous binary tree. Here problem description and explanation.

package main
import "fmt"
/* 
  Go program for
  Check if binary tree is continuous tree
  Using recursion
*/
// Binary Tree Node
type TreeNode struct {
	data int
	left * TreeNode
	right * TreeNode
}
func getTreeNode(data int) * TreeNode {
	// return new TreeNode
	return &TreeNode {
		data,
		nil,
		nil,
	}
}
type BinaryTree struct {
	root * TreeNode
}
func getBinaryTree() * BinaryTree {
	// return new BinaryTree
	return &BinaryTree {
		nil,
	}
}
func(this BinaryTree) absValue(num int) int {
	if num < 0 {
		return -num
	}
	return num
}
// Check tree is continuous or not
func(this BinaryTree) isContinuous(node * TreeNode) bool {
	if node != nil {
		if (node.left != nil && 
			this.absValue(node.data - node.left.data) != 1) || 
		   (node.right != nil && 
		   	this.absValue(node.data - node.right.data) != 1) {
			// Case
			// When fail continuous tree rule
			return false
		}
		if this.isContinuous(node.left) && 
		   this.isContinuous(node.right) {
			return true
		}
		// When node value is not satisfied
		//  continuous tree properties
		return false
	}
	return true
}
func main() {
	// Create new tree
	var tree * BinaryTree = getBinaryTree()
	/*  
	   Binary Tree
	   ------------
	       5
	     /   \
	    4     4
	   /     /  \
	  3     5    3
	   \
	    2
	        
	*/
	// Add tree node
	tree.root = getTreeNode(5)
	tree.root.left = getTreeNode(4)
	tree.root.right = getTreeNode(4)
	tree.root.left.left = getTreeNode(3)
	tree.root.right.right = getTreeNode(3)
	tree.root.right.left = getTreeNode(5)
	tree.root.left.left.right = getTreeNode(2)
	if tree.isContinuous(tree.root) == true {
		fmt.Println("Continuous Tree ")
	} else {
		fmt.Println("Not Continuous Tree ")
	}
	// Case 2
	/* 
	       5
	     /   \
	    4     4
	   /     /  \
	  3     5    3
	   \
	    1  <--- change value
	        
	*/
	tree.root.left.left.right.data = 1
	if tree.isContinuous(tree.root) == true {
		fmt.Println("Continuous Tree ")
	} else {
		fmt.Println("Not Continuous Tree ")
	}
}

Output

Continuous Tree
Not Continuous Tree