private void DepthClick(object sender, RoutedEventArgs e)
        {
            var connector = Connector;

            foreach (var security in SecurityPicker.SelectedSecurities)
            {
                var window = _quotesWindows.SafeAdd(security, s =>
                {
                    // subscribe on order book flow
                    connector.SubscribeMarketDepth(security);

                    // create order book window
                    var wnd = new QuotesWindow
                    {
                        Title = security.Id + " " + LocalizedStrings.MarketDepth
                    };
                    wnd.MakeHideable();
                    return(wnd);
                });

                if (window.Visibility == Visibility.Visible)
                {
                    window.Hide();
                }
                else
                {
                    window.Show();
                    //window.DepthCtrl.UpdateDepth(connector.GetMarketDepth(security));
                }

                if (!_initialized)
                {
                    connector.MarketDepthReceived += TraderOnMarketDepthReceived;
                    _initialized = true;
                }
            }
        }