有时候，有时候，需要设置下头信息呀有没有?! 比如设置下缓存时间，返回内容类型啊有没有?! 在load函数还有后面会遇到的form actions, hooks和API routes里可以使用setHeaders:

Inside a load function (as well as in form actions, hooks and API routes, which we’ll learn about later) you have access to a setHeaders function, which — unsurprisingly — can be used to set headers on the response. Most commonly, you’d use it to customise caching behaviour with the Cache-Control response header, but for the sake of this tutorial we’ll do something less advisable and more dramatic:

export function load({ setHeaders }) {
	setHeaders({
		'Content-Type': 'text/plain'
	});
}

(可能需要刷新下Iframe才能看到效果)

(You may need to reload the iframe to see the effect.)