The code below provides a TreeNode class. The TreeNode class is missing code for the node insertion and two of the types of binary tree traversals $($postorder$,$ preorder$).$ The node insertion for a binary search tree must ensure that the nodes on the left are all less than the parent node and the nodes on the right are all greater. Your assignment is to complete the insert method for the binary search tree, the missing traversals, and add a new method to search for a specific object $($by name or by an attribute value$)$ that returns a Boolean true if the object$/$value is in the tree. In order to demonstrate the tree, you will populate the tree with your own custom objects from your inheritance subclass, demonstrate the new traversals and the search method. Be sure to identify how you are comparing your custom objects for appropriate placement in the binary search tree using comments in your inheritance subclass code.

Hint:

$1)$ Call insertNode method to insert node in the binary tree. Within insertNode method, insert method is called$($You have to write code for this.$)$

$2)$ insert method is called recursively.

$3)$ Do not insert new nodes as follows: root.left, root.left.right, etc. Make use of insertNode methods. Traversal helper methods are recursive.

$//$class TreeNode definition

public class TreeNode$>\{$

$//$ package access members

TreeNode leftNode; $//$ left node

T data; $//$ node value

TreeNode rightNode; $//$ right node

$//$ constructor initializes data and makes this a leaf node

public TreeNode$($T nodeData$)\{$

data $=$ nodeData;

leftNode $=$ rightNode $=$ null; $//$ node has no children

$\}$

$//$ locate insertion point and insert new node; ignore duplicate values

public void insert$($T insertValue$)\{$

$//$ insert in left subtree

$**$YOUR CODE GOES HERE

$//$ insert in right subtree

$**$ YOUR CODE GOES HERE

$//$class Tree definition

public class Tree$>\{$

private TreeNode root;

$//$ constructor initializes an empty Tree of integers

public Tree$()\{$

root $=$ null;

$\}$

$//$ insert a new node in the binary search tree

public void insertNode$($T insertValue$)\{$

if $($root $==$ null$)\{$

root $=$ new TreeNode$<>($insertValue$)$; $//$ create root node

$\}$

else $\{$

root.insert$($insertValue$)$; $//$ call the insert method

$\}$

$\}$

$//$ begin preorder traversal

public void preorderTraversal$()\{$

preorderHelper$($root$)$;

$\}$

$//$ recursive method to perform preorder traversal

private void preorderHelper$($TreeNode node$)\{$

$**$ YOUR CODE GOES HERE

$//$ begin inorder traversal

public void inorderTraversal$()\{$

inorderHelper$($root$)$;

$\}$

$//$ recursive method to perform inorder traversal

private void inorderHelper$($TreeNode node$)\{$

if $($node $==$ null$)\{$

return;

$\}$

inorderHelper$($node$.$leftNode$)$; $//$ traverse left subtree

System.out.printf$("\%$s $",$ node.data$)$; $//$ output node data

inorderHelper$($node$.$rightNode$)$; $//$ traverse right subtree

$\}$

$//$ begin postorder traversal

public void postorderTraversal$()\{$

postorderHelper$($root$)$;

$\}$

$//$ recursive method to perform postorder traversal

private void postorderHelper$($TreeNode node$)\{$

$**$ YOUR CODE GOES HERE

Inheritance subclass:

public class Milk extends foodClass$\{$

$//$ Attributes specific to Milk

private String typeOfMilk;

private double fatContent; $//$ Fat content in percentage

$//$ Default Constructor

public Milk$()\{$

super$()$;

this.typeOfMilk $=$ "default";

this.fatContent $=0\mathrm{.}0$;

$\}$

$//$ Overloaded Constructor initializing specific attributes

public Milk$($String name, int calories, String typeOfMilk, double fatContent$)\{$

super$($name$,$ calories$)$;

this.typeOfMilk $=$ typeOfMilk;

this.fatContent $=$ fatContent;

$\}$

$//$ Override toString method

@Override

public String toString$()\{$

return super.toString$()+"|$ Type of Milk: $"+$ typeOfMilk $+"|$ Fat Content: $"+$ fatContent $+"\%"$;

$\}$

$\}$