Not Found - 404 (NotFoundError)

[cute-master]

I like your acorn very much, can you help me how to catch this error and respond to custom data? thanks.

Not Found - 404
http://localhost:10000/
Stack trace:

NotFoundError: http://localhost:10000/
at createHttpError (https://deno.land/std@0.190.0/http/http_errors.ts:199:10)
at Router.#notFound (https://deno.land/x/acorn@0.3.0/router.ts:974:9)
at Router.#handle (https://deno.land/x/acorn@0.3.0/router.ts:956:32)
at eventLoopTick (ext:core/01_core.js:183:11)