Support for Vary header in response headers.

[INRIX-Xiaodi-Huang]

I make the following request through unirest to get an image.
Request Headers
view source
Accept:text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,/;q=0.8
Accept-Encoding:gzip, deflate, sdch, br
Accept-Language:en-US,en;q=0.8
Connection:keep-alive
Cookie:_ga=*************************
Host:blah.blah.com
If-None-Match:d41d8cd98f00b204e9800998ecf8427e
Upgrade-Insecure-Requests:1
User-Agent:*******************
Query String Parameters
view source
view URL encoded
format:sugar-html-json
platform:base
_hash:4f52279c-0796-11e7-8cc2-02135a7c6b1f

The response is:
Request URL:*****************************
Request Method:GET
Status Code:304 Not Modified
Remote Address:********************
Response Headers
view source
Cache-Control:max-age=0, private
Connection:keep-alive
Date:Mon, 13 Mar 2017 02:43:04 GMT
Expires:
Server:Apache
Vary:Accept-Encoding

Since content-encoding is missing from response headers, unirest doesn't unzip the response. I have no trouble seeing the image in browsers. Likewise if I leave accept-encoding header blank in my request, I am able to get the image in unirest.