Just giving 2016.2 its first spin and I noticed the unused 'response' param below isn't being highlighted? normally this would be underlined with wavy grey and a warning mark in the gutter. I've checked my settings and the inspection is turned on, even tried toggling it on & off but IDEA still isn't working? its definitely unused and I'm sure 2016.1 was nagging me about it 20mins ago. It a freshly rebuilt index and the only project I've opened in 2016.2 so far.
This is on Centos 6.5(ish) I think.