@Override
  public CustomPropertiesPanel getRowColumnPropertiesPanel(RadContainer container, boolean isRow, int[] selectedIndices) {
    if (myPropertiesPanel == null) {
      myPropertiesPanel = new GridLayoutColumnProperties();
    }
    myPropertiesPanel.showProperties(container, isRow, selectedIndices);
    return myPropertiesPanel;
  }
@Override
  public CustomPropertiesPanel getRowColumnPropertiesPanel(RadContainer container, boolean isRow, int[] selectedIndices)