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 String getAggregationFunction(
			CrosstabReportItemHandle crosstab, AggregationCellHandle cell )
	{
		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.getAggregateFunction( ) != null )
					return columnHandle.getAggregateFunction( );
			}
		}
		return null;
	}
	/**
	 * Gets the aggregation function for this cell.
	 * 
	 * @param crosstab
	 * @param cell
	 * @param function
	 * @return
	 * @throws SemanticException