$(window).on('unload', function() {
        db.flipCounter.get(gon.slug, function(obj) {
            var payload = JSON.stringify({
                slug: gon.slug,
                localFlipCount: obj.fc,
                time: Date.now()
            })

            navigator.sendBeacon('/analytics', csrfProtect(payload))

        })
    })

    function csrfProtect(payload) {
        var param = $("meta[name=csrf-param]").attr("content")
        var token = $("meta[name=csrf-token]").attr("content")

        if (param && token) payload[param] = token
        return new Blob([JSON.stringify(payload)], { type: "application/json; charset=utf-8" })
    }