provide OkHttp with an HTTP request, you’re describing the request at a high-level: _“fetch me this URL with these headers.”_ For correctness and efficiency, OkHttp rewrites your request before transmitting it.

OkHttp may add headers that are absent from the original request, including `Content-Length`, `Transfer-Encoding`, `User-Agent`, `Host`, `Connection`, and `Content-Type`. It will add an `Accept-Encoding` header for transparent response compression unless the header is already present....