import { Headers } from "https://deno.land/x/deno@v1.30.2/ext/fetch/lib.deno_fetch.d.ts";
The Symbol.iterator well-known symbol specifies the default iterator for this Headers object
x/deno/ext/fetch/lib.deno_fetch.d.ts>Headers#[Symbol.iterator]
import { Headers } from "https://deno.land/x/deno@v1.30.2/ext/fetch/lib.deno_fetch.d.ts";
The Symbol.iterator well-known symbol specifies the default iterator for this Headers object