SimpleHistory::setup_cron PHP Method

    function setup_cron()
    {
        add_filter("simple_history/maybe_purge_db", array($this, "maybe_purge_db"));
        if (!wp_next_scheduled('simple_history/maybe_purge_db')) {
            wp_schedule_event(time(), 'daily', 'simple_history/maybe_purge_db');
            //error_log("not scheduled, so do schedule");
        } else {
            //error_log("is scheduled");
        }
        // Remove old schedule (only author dev sites should have it)
        $old_next_scheduled = wp_next_scheduled('simple_history/purge_db');
        if ($old_next_scheduled) {
            wp_unschedule_event($old_next_scheduled, 'simple_history/purge_db');
        }
    }