@Override
		public String getToolTipText(MouseEvent e)
		{
			String tip = getSelectionCellsHandler().getToolTipText(e);

			if (tip == null)
			{
				Object cell = getCellAt(e.getX(), e.getY());

				if (cell != null)
				{
					if (hitFoldingIcon(cell, e.getX(), e.getY()))
					{
						tip = mxResources.get("collapse-expand");
					}
					else
					{
						tip = graph.getToolTipForCell(cell);
					}
				}
			}

			if (tip != null && tip.length() > 0)
			{
				return tip;
			}

			return super.getToolTipText(e);
		}