Bug 207825 Crosstab gives wrong default for Totals on Count
xtab/org.eclipse.birt.report.item.crosstab.core/src/org/eclipse/birt/report/item/crosstab/core/de/internal/CrosstabModelUtil.java
*/
	public static void setAggregationFunction(
			CrosstabReportItemHandle crosstab, AggregationCellHandle cell,
			String function ) throws SemanticException
	{
		assert crosstab != null;
		assert cell != null;
		assert cell.getCrosstab( ) == crosstab;
		ReportItemHandle crosstabModel = (ReportItemHandle) crosstab.getModelHandle( );
		List contents = cell.getContents( );
		for ( int index = 0; index < contents.size( ); index++ )
		{
			DesignElementHandle content = (DesignElementHandle) contents.get( index );
			if ( content instanceof DataItemHandle )
			{
				String columnName = ( (DataItemHandle) content ).getResultSetColumn( );
				ComputedColumnHandle columnHandle = crosstabModel.findColumnBinding( columnName );
				if ( columnHandle != null )
					columnHandle.setAggregateFunction( function );
			}
		}
	}
	/**
	 * Locates the cell which controls the column with for given cell
	 * 
	 * @param crosstabItem
	 * 
	 * @param cell
	 * @return
	 */