Bug 208419 NullPointerException at CubeResultSet close
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/DataPresentationEngine.java
{
		super( context );
		
		DataSessionContext dteSessionContext = new DataSessionContext(
				DataSessionContext.MODE_PRESENTATION, null, context
						.getSharedScope( ) );
		dteSessionContext.setDocumentReader( reader );
		DataEngineContext dteEngineContext = dteSessionContext
				.getDataEngineContext( );
		dteEngineContext.setLocale( context.getLocale( ) );
		String tempDir = getTempDir( context );
		if ( tempDir != null )
		{
			dteEngineContext.setTmpdir( tempDir );
		}
		dteSession = DataRequestSession.newSession( dteSessionContext );
		
		
		loadDteMetaInfo( reader );
	}
	/**
	 * prepare the queries defined in the report.
	 */
	public void prepare( Report report, Map appContext )
	{
		
		new ReportQueryBuilder( report, context ).build( );
		doPrepareQuery( report, appContext );
	}