Bug 417305 A sample chart has no data
chart/org.eclipse.birt.chart.examples/src/org/eclipse/birt/chart/examples/view/models/WorkingWithBIRTDataEngine.java
evaluator = prepareRowExpressionEvaluator( cwaBar, expressions );
			
			
			Generator.instance( ).bindData( evaluator, cwaBar, context );
		}
		catch ( BirtException e )
		{
			throw new ChartException( ChartExamplesPlugin.ID,
					ChartException.DATA_BINDING,
					e );
		}
		return cwaBar;
	}
	/**
	 * Uses BIRT data engine to do query and wraps data with
	 * <code>IDataRowExpressionEvaluator</code> for chart doing data binding.
	 * 
	 * @return
	 * @throws BirtException
	 */
	private IDataRowExpressionEvaluator prepareRowExpressionEvaluator(
			ChartWithAxes chart, String[] expressions ) throws BirtException
	{
		
		OdaDataSourceDesign odaDataSource = newDataSource( );
		OdaDataSetDesign odaDataSet = newDataSet( odaDataSource );
		
		QueryDefinition query = createQueryDefinition( odaDataSet, expressions );