Are empty header values equivalent to absent ones?

[robhanlon22]

There are a lot of falsey checks in this library rather than undefined checks. Here's one, for example. I'm wondering if these should be switched to null/undefined checks (x == null) as it appears that empty header values are valid according to the HTTP RFC. I'm wondering this is that I'm working with an API that is behaving weirdly (returns Pragma: no-cache alongside Cache-Control: ) when I send over a Cache-Control: max-age=3600 header in the request, which is causing this library to consider the response to not be cacheable. Thx!

[kornelski]

Oh, interesting edge case. I guess "header present" does include "" values, so a stricter change would be ok.