scrub_env!

# File actionpack/lib/action_controller/test_case.rb, line 642
        def scrub_env!(env)
          env.delete_if do |k, _|
            k.start_with?("rack.request", "action_dispatch.request", "action_dispatch.rescue")
          end
          env["rack.input"] = StringIO.new
          env.delete "CONTENT_LENGTH"
          env.delete "RAW_POST_DATA"
          env
        end