Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/DataEngineImpl.java
{
		if ( context.getMode( ) != DataEngineContext.MODE_PRESENTATION )
			throw new DataException( ResourceConstants.WRONG_STATUS );
		return new QueryResults( this.context, queryResultID );
	}
	
	/**
	 * Provides the definition of a data source to Data Engine. A data source
	 * must be defined using this method prior to preparing any report query
	 * that uses such data source. <br>
	 * Data sources are uniquely identified name. If specified data source has
	 * already been defined, its definition will be updated with the content of
	 * the provided DataSourceDesign
	 */
	public void defineDataSource( IBaseDataSourceDesign dataSource )
			throws DataException
	{
		logger.entering( DataEngineImpl.class.getName( ),
				"defineDataSource",
				dataSource == null ? null : dataSource.getName( ) );
		if ( dataSource == null )
		{
			NullPointerException e = new NullPointerException( "dataSource param cannot be null" );
			logger.logp( Level.WARNING,
					DataEngineImpl.class.getName( ),
					"defineDataSource",
					"dataSource param cannot be null",
					e );
			throw e;
		}