This was one of the test cases you asked me to add and was/is bizarrely continuing to fail. Super weird, because I could see the header present but it'd never reach the response object. 

After diving down the rabbit hole, it turns out that, at least on Netty, "Transfer-Encoding" headers are stripped out if there's no body. You can see this logic in `HttpClientCodec#isContentAlwaysEmpty` (true if head) the state proceeds to SKIP_CONTROL_CHARS which leads us to strip out Transfer-Encoding at `HttpmessageDecoder:205`.

I'm not actually sure how HEAD should behave with a Chunked response; going to validate the behavior in other HTTP clients and will update this comment.