For this Question: Given a binary tree, find height of it.

        1
     /     \
   10      39
  /
5

The above tree has a height of 3.
Note: Height of empty tree is considered 0.<b>User Task:</b>
Since this will be a functional problem. You don't have to take input. You just have to complete the function <b>getHeight()</b> that takes "root" node as parameter and returns the height. The printing is done by the driver code. 

Constraints:
1 < = T < = 100
1 < = N < = 10^5
1 < = node values < = 10^5

Sum of "N" over all testcases does not exceed 10^5

For <b>Custom Input:</b>
First line of input should contains the number of test cases T. For each test case, there will be two lines of input.
First line contains number of nodes N. Second line will be a string representing the tree as described below: 
The values in the string are in the order of level order traversal of the tree where, numbers denote node values, and a character “N” denotes NULL child.
<b>Note:</b> If a node has been declared Null using 'N', no information about its children will be given further in the array.Return the height of the tree.Sample Input:
1
3
1 2 3

Sample Output:
2

Explanation:
Testcase1: The tree is
        1
     /      \
   2        3
So, the height would be 2., I have written this Solution Code:  static int getHeight(Node node) {
 if (node == null) {
        return 0;
    }
    return 1 + Math.max( getHeight(node.left), getHeight(node.right) );

    }, In this Programming Language: Java, Now tell me if this Code is compilable or not?