well I got that from the documentation but problem is that using {{ request.headers|pprint }} in templates causing pages to crash resulting in white screen of death.
Well I am trying to just print headers right now, but I actually want to use one of the headers in if condition to display some blocks from template which is behaving very weird (end up giving the same white screen of death at page) in design manager when I try to use request.headers or request.cookies variables in a if condition inside a template.
{{ request.headers }} {% if request.headers['some-header'] %}