class Node {
    constructor(value) {
        this.value = value
        this.next = null
        this.prev = null
    }
}

class DoubleLinkedList {
    constructor(value) {
        const newNode = new Node(value)
        this.head = newNode
        this.tail = this.head
        this.length = 1
    }

    push(value) {
        const newNode = new Node(value)
        if (!this.head) {
            this.head = newNode
            this.tail = newNode
        } else {
            this.tail.next = newNode
            newNode.prev = this.tail
            this.tail = newNode
        }
        this.length++
        return this
    }

    pop() {
        
    }
}

let myDoubleLinkedList = new DoubleLinkedList(1)
myDoubleLinkedList.push(2)