* @return
	 */
	public ArrayList<BiffRec> getCellsByCol( int colNum ) throws CellNotFoundException
	{
		List<? extends BiffRec> theCells = cellsByCol.get( colNum );
		if( theCells.size() == 0 )
		{
			throw new CellNotFoundException( sheetname, 0, col );
		}

		Iterator<? extends BiffRec> i = theCells.iterator();
		while( i.hasNext() )
		{
			BiffRec biffrec = i.next();
			if( biffrec.getOpcode() == MULBLANK )
			{
				((Mulblank) biffrec).setCurrentCell( (short) colNum );
			}
		}
		return new ArrayList<>( theCells );
	}