[3] Add prefetch and prerender initiators (yoavweiss著, ) https://github.com/whatwg/fetch/commit/d5d084096392f2c47841308952a76751bafdd375
[4] Add a `prefetch` initiator by yoavweiss · Pull Request #659 · whatwg/fetch () https://github.com/whatwg/fetch/pull/659
[5] Request.destination for `<link rel=prefetch>` · Issue #658 · whatwg/fetch () https://github.com/whatwg/fetch/issues/658