public function enqueueGumroadOverlayLibs()
    {
        if (($data = $this->didEnqueueLibs(__METHOD__))) {
            return $data; // Did this already.
        } // We only need to enqueue once.

        $data = [
            'scripts' => [
                'gumroad-overlay' => [
                    'sri'     => '', // No SRI, updated by Gumroad.
                    'url'     => '//gumroad.com/js/gumroad-overlay.js',
                ],
            ],
        ];
        return $this->enqueueLibs(__METHOD__, $data);
    }