/// <summary>
        /// Unbinds the Activity from the Custom Tabs Service. </summary>
        /// <param name="activity"> the activity that is connected to the service. </param>
        public virtual void UnbindCustomTabsService(Android.App.Activity activity)
        {
            if (custom_tabs_service_connection == null)
            {
                return;
            }
            activity.UnbindService(custom_tabs_service_connection);
            custom_tabs_client             = null;
            custom_tabs_session            = null;
            custom_tabs_service_connection = null;

            return;
        }