import { Deno } from "https://deno.land/x/deno@v1.28.0/cli/dts/lib.deno.ns.d.ts";
const { FsFile } = Deno;
Close the file. Closing a file when you are finished with it is important to avoid leaking resources.
const file = await Deno.open("my_file.txt");
// do work with "file" object
file.close();