Fetch.ResponseSourceRequest responses.
The type for response initialisation objects.
init () is a response initialisation object with given parameters.
v ~init ~body is a response with parameters init and body body.
error is a network error response.
redirect ~status url is a redirect response to url with status status.
as_body r is the body interface of r.
ok r is true if the response r is successful.
redirected r is true if the reponse is the result of a redirection.
status_text r is the status text of r.