Hi,
The behavior I can see from the TCK is that the header map returned by HandshakeResponse respects case for keys and values, but should be case insensitive for keys on lookups. This is very coherent with HTTP (and Servlets) so if my interpretation is right I fully agree with this, but is not specified anywhere and is not so intuitive due to the collection type used here.
For example, the javadoc for the getHeaders method is: Return the list of Http headers sent by the web socket server.
This javadoc entry would be the best location to describe the desired behavior.
Thanks,
Rémy