public class TwoThreeTree$>\{$

private TreeNode root;

private boolean inserted;

public TwoThreeTree$()\{$

root $=$ null;

inserted $=$ false;

$\}$

public TwoThreeTree$($T item$)\{$

root $=$ new TreeNode$($item$)$;

inserted $=$ false;

$\}$

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

root $=$ insertItem$($root$,$ insertKey$)$;

inserted $=$ false;

$\}$

public void retrieve$($T searchKey$)\{$

TreeNode treeNode $=$ retrieveItem$($root$,$ searchKey$)$;

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

System.out.println$($searchKey $+"$ is not present in $2-3$ tree."$)$;

$\}$ else $\{$

System.out.println$($searchKey $+"$ is present in $2-3$ tree."$)$;

$\}$

$\}$

public void remove$($T deleteKey$)\{$

root $=$ removeItem$($root$,$ deleteKey$)$;

$\}$private TreeNode insertItem$($TreeNode treeNode, T insertKey$)\{//$complete this implementation $\}$

private TreeNode insertItem$($TreeNode treeNode, T insertKey$)\{$

$//$ Implement insertItem here.

$\}$

private TreeNode removeItem$($TreeNode treeNode, T deleteKey$)\{$

$//$ Implement removeItem here

$//$ The error will go away once you implement and returns an item

$\}$

private void split$($TreeNode treeNode, T item$)\{...\}$

public void setPreorder$()\{$

preorder$($root$)$;

$\}$

public void setInorder$()\{$

inorder$($root$)$;

$\}$

public void setPostorder$()\{$

postorder$($root$)$;

$\}$

private void preorder$($TreeNode treeNode$)\{$

$//$ implement preorder here

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

return;

$\}$

$\}$

private void inorder$($TreeNode treeNode$)\{$

$//$ implement inorder here

$\}$

private void postorder$($TreeNode treeNode$)\{$

$//$ implement postorder here

$\}$

$\}$

public class TreeNode $\{$

private T small;

private T large;

TreeNode leftChild;

TreeNode rightChild;

TreeNode middleChild;

TreeNode parent;

TreeNode temp;

public TreeNode$()\{$

$//$ no$-$arg constructor

this.small $=$ null;

this.large $=$ null;

this.leftChild $=$ null;

this.rightChild $=$ null;

this.middleChild $=$ null;

this.parent $=$ null;

this.temp $=$ null;

$\}$

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

$//$ Initializes tree node with a small item and no children.

this.small $=$ small;

this.large $=$ null;

this.leftChild $=$ null;

this.rightChild $=$ null;

this.middleChild $=$ null;

this.parent $=$ null;

this.temp $=$ null;

$\}$

public TreeNode$($T small, T large$)\{$

$//$ Initializes tree node with a small and a large items and no children.

this.small $=$ small;

this.large $=$ large;

this.leftChild $=$ null;

this.rightChild $=$ null;

this.middleChild $=$ null;

this.parent $=$ null;

this.temp $=$ null;

$\}$

public TreeNode$($T small, T large, TreeNode leftChild, TreeNode rightChild, TreeNode middleChild,

TreeNode parent, TreeNode temp$)\{$

this.small $=$ small;

this.large $=$ large;

this.leftChild $=$ leftChild;

this.rightChild $=$ rightChild;

this.middleChild $=$ middleChild;

this.parent $=$ parent;

this.temp $=$ temp;

$\}$

public T getSmallItem$()\{$

return small;

$\}$

public void setSmallItem$($T small$)\{$

this.small $=$ small;

$\}$

public T getLargeItem$()\{$

return large;

$\}$

public void setLargeItem$($T large$)\{$

this.large $=$ large;

$\}$

public TreeNode getLeftChild$()\{$

return leftChild;

$\}$

public void setLeftChild$($TreeNode leftChild$)\{$

this.leftChild $=$ leftChild;

$\}$

public TreeNode getRightChild$()\{$

return rightChild;

$\}$

public void setRightChild$($TreeNode rightChild$)\{$

this.rightChild $=$ rightChild;

$\}$

public TreeNode getMidChild$()\{$

return middleChild;

$\}$

public void setMidChild$($TreeNode middleChild$)\{$

this.middleChild $=$ middleChild;

$\}$

public TreeNode getParentNode$()\{$

return parent;

$\}$

public void setParentNode$($TreeNode parent$)\{$

this.parent $=$ parent;

$\}$

public TreeNode getTempChild$()\{$

return temp;

$\}$

public void setTempChild$($TreeNode temp$)\{$

this.temp $=$ temp;

$\}$

$\}//$ end TreeNode

import java.util.Scanner;

public class DriverTwoThreeTree $\{$

public static void main$($String$[]$ args$)\{$

Scanner input $=$ new Scanner$($System$.$in$)$;

TwoThreeTree tttree $=$ new TwoThreeTree$()$;

$//$complete the rest as per the instruction

$\}$

$\}$