interface DoublyLinkedListimport { type DoublyLinkedList } from "https://deno.land/x/masx200_leetcode_test@10.3.5/design-linked-list/DoublyLinkedList.ts"; Type ParametersoptionalT = anyPropertiesoptionalval: Toptionalnext: DoublyLinkedList<T> | nulloptionalprev: DoublyLinkedList<T> | nullfunction DoublyLinkedListimport { DoublyLinkedList } from "https://deno.land/x/masx200_leetcode_test@10.3.5/design-linked-list/DoublyLinkedList.ts"; DoublyLinkedList<T = any>(val?: T,next?: DoublyLinkedList<T>,prev?: DoublyLinkedList<T>,): DoublyLinkedList<T>Type ParametersoptionalT = anyParametersoptionalval: Toptionalnext: DoublyLinkedList<T>optionalprev: DoublyLinkedList<T>ReturnsDoublyLinkedList<T>