private void OnRemoveOptionClick(object sender, RoutedEventArgs e)
 {
     ValidateDeleteButton();
     if (OptionsCollection.Any() && IsSelectedItem())
     {
         var index = expressionsListBox.SelectedIndex;
         OptionsCollection.RemoveAt(index);
         var count = OptionsCollection.Count;
         if (count > 0)
         {
             if (index >= count)
             {
                 index = count - 1;
             }
             expressionsListBox.SelectedIndex = index;
         }
         else
         {
             if (!string.IsNullOrEmpty(_expressionEditor.ExpressionText))
             {
                 _expressionEditor.ExpressionText = string.Empty;
             }
         }
     }
 }