Hide unrelated headers, prepare to render request.

Instead of sending back a essentially blank response, it’d be nice (when we were demoing things like ETag and Last-Modified) if we could see the full set of request headers that were sent from the browser.

Since we can’t see these post-browser mangling, we’ll need to rely on the server to send them back in the response.

Good thing we had an essentially blank response! We can just send a JSON blob of request headers in the response, which works great.

Except that now we have some headers that change value seemingly for no reason — Content-Length, for example.

Since there’s really no reason why you’d care about Connection, Content-Type, or Content-Length while looking at caching, we can safely hide them away.

Next up, let’s render the request headers out to the view somewhere.