вставка в лист

#include <iostream>
using namespace std;

class MyList
{
public:
    class Node*
    {
        int data;
        Node* prev;
        Node* next;
    }

    Node* head;
    Node* tail;
    size_t size = 0;

    void GetN(size_t n)
    {
        Node* current = head;
        for( size_t i = 0; i < n - 1; ++i)
        {
            current = current->next;
        }
    }

    Node* push_back(int data)
    {
        Node* newNode = new Node;
        newNode->data = data;
        if (head == nullptr)
        {
            head = newNode;
            tail = newNode;
        }
        else
        {
            tail->next = newNode;
            newNode->prev = tail;
            tail = newNode;
        }
        size++;
    }

    void pop_back()
    {
        if (head == nullptr)
        {
            return;
        }

        if (head == tail)
        {
            delete tail;
            head = nullptr;
            tail = nullptr;
        }
        else
        {
            tail->prev->next = nullptr;
            Node* newTail = tail->prev;
            delete tail;
            tail = newTail;
        }
    }
}

 int main() {


}