# File lib/rack/protection/json_csrf.rb, line 16
      def call(env)
        status, headers, body = app.call(env)
        if headers['Content-Type'].to_s.split(';', 2).first =~ /^\s*application\/json\s*$/
          if referrer(env) != Request.new(env).host
            result = react(env)
            warn env, "attack prevented by #{self.class}"
          end
        end
        result or [status, headers, body]
      end