code: @Override
  	protected Icon getIcon(JTable table, int column) {
  		SortKey sortKey = getSortKey(table, column);
  		if (sortKey != null && table.convertColumnIndexToView(sortKey.getColumn()) == column) {
  			SortOrder sortOrder = sortKey.getSortOrder();
  			switch (sortOrder) {
  			case ASCENDING:
  				return VerticalSortIcon.ASCENDING;
  			case DESCENDING:
  				return VerticalSortIcon.DESCENDING;
  			case UNSORTED:
  				return VerticalSortIcon.ASCENDING;
  			}
  		}
  		return null;
  	}
docs: Overridden to return a rotated version of the sort icon.
  
  @param table
  the <code>JTable</code>.
  @param column
  the colummn index.
  @return the sort icon, or null if the column is unsorted.