public ToolBoxGrid()
 {
     SizeChanged +=
         delegate
     {
         var lastRowDefinition = RowDefinitions.Last();
         var rowsHeight        = RowDefinitions.Sum(rd => rd.ActualHeight);
         lastRowDefinition.Height = new GridLength(Math.Max(LastRowMinHeight, ActualHeight - rowsHeight + lastRowDefinition.ActualHeight));
     };
 }