private void setLineSelection(LinkLineNode node, bool selected)
 {
     if (node != null)
     {
         if (selected)
         {
             node.SelectLine(selected);
         }
         else
         {
             bool bCanDeSelect = true;
             if (_selectedLine != null)
             {
                 if (_selectedLine.IsOnTheLine(node))
                 {
                     bCanDeSelect = false;
                 }
             }
             if (bCanDeSelect)
             {
                 node.SelectLine(selected);
             }
         }
     }
 }