Node class, programming homework help

Consider the LinkedList class and the Node class that we saw in lecture. The LinkedList class basically represents a singly linked list. Now, for this lab, consider a doubly linked list, i.e. each node has a next and previous pointers to the next and previous node, respectively. Modify the Node class to reflect this change and implement the following methods for DoublyLinkedList class:addFirstaddLastaddAtIndexremoveFirstremoveLastremoveAtIndexNote: We saw how to implement these methods for a singly linked list and the code is added as an attachment.Submit a zipped file containing the Visual Studio Project folder.use this for c++#include <stdexcept>using namespace std;template<typename T>class Node{public: T element; // Element contained in the node Node<T> *next; // Pointer to the next node  Node() // No-arg constructor { next = NULL; } Node(T element) // Constructor { this->element = element; next = NULL; }};template<typename T>class LinkedList{public: LinkedList(); void addFirst(T element); void addLast(T element); T removeFirst() throw (runtime_error); T removeLast();  void add(int index, T element);  T removeAt(int index);private: Node<T> *head, *tail; int size;};template<typename T>LinkedList<T>::LinkedList(){ head = tail = NULL; size = 0;}template<typename T>void LinkedList<T>::addFirst(T element){ Node<T> *newNode = new Node<T>(element); newNode->next = head; head = newNode; size++; if (tail == NULL) tail = head;}template<typename T>void LinkedList<T>::addLast(T element){ if (tail == NULL) { head = tail = new Node<T>(element); } else { tail->next = new Node<T>(element); tail = tail->next; } size++;}template<typename T>void LinkedList<T>::add(int index, T element){ if (index == 0) addFirst(element); else if (index >= size) addLast(element); else { Node<T> *current = head; for (int i = 1; i < index; i++) current = current->next; Node<T> *temp = current->next; current->next = new Node<T>(element); (current->next)->next = temp; size++; }}template<typename T>T LinkedList<T>::removeFirst() throw (runtime_error){ if (size == 0) throw runtime_error("No elements in the list"); else { Node<T> *temp = head; head = head->next; size--; T element = temp->element; delete temp; return element; }}template<typename T>T LinkedList<T>::removeLast(){ if (size == 0) throw runtime_error("No elements in the list"); else if (size == 1) { Node<T> *temp = head; head = tail = NULL; size = 0; T element = temp->element; delete temp; return element; } else { Node<T> *current = head; for (int i = 0; i < size - 2; i++) current = current->next; Node<T> *temp = tail; tail = current; tail->next = NULL; size--; T element = temp->element; delete temp; return element; }}template<typename T>T LinkedList<T>::remove(int index){ if (index < 0 || index >= size) throw runtime_error("Index out of range"); else if (index == 0) return removeFirst(); else if (index == size - 1) return removeLast(); else { Node<T> *previous = head; for (int i = 1; i < index; i++) { previous = previous->next; } Node<T> *current = previous->next; previous->next = current->next; size--; T element = current->element; delete current; return element; }}