instance method non_kwarg_request_warning

# File actionpack/lib/action_dispatch/testing/integration.rb, line 373
        def non_kwarg_request_warning
          ActiveSupport::Deprecation.warn(<<-MSG.strip_heredoc)
            Using positional arguments in integration tests has been deprecated,
            in favor of keyword arguments, and will be removed in Rails 5.1.

            Deprecated style:
            get "/profile", { id: 1 }, { "X-Extra-Header" => "123" }

            New keyword style:
            get "/profile", params: { id: 1 }, headers: { "X-Extra-Header" => "123" }
          MSG
        end