如何获得DateTime持续时间？

DateTime startTime = DateTime.Now;
// 执行任务代码
DateTime endTime = DateTime.Now;
TimeSpan duration = endTime - startTime;

LocalDateTime startTime = LocalDateTime.now();
// 执行任务代码
LocalDateTime endTime = LocalDateTime.now();
Duration duration = Duration.between(startTime, endTime);

import datetime

startTime = datetime.datetime.now()
# 执行任务代码
endTime = datetime.datetime.now()
duration = endTime - startTime

let startTime = new Date();
// 执行任务代码
let endTime = new Date();
let duration = endTime - startTime;