class defaultimport { default } from "https://deno.land/x/masx200_leetcode_test@10.6.2/design-underground-system/index.ts"; Constructorsnewdefault()MethodscheckIn(id: number,stationName: string,t: number,): voidcheckOut(id: number,stationName: string,t: number,): voidgetAverageTime(startStation: string, endStation: string): number