if( false ) this.loadForIV( );
	private void prepare( ) throws DataException	{		if ( rowDis == null )		{			rowIs = context.getInputStream( queryResultID,					subQueryID,					DataEngineContext.EXPR_VALUE_STREAM );			rowBis = new BufferedInputStream( rowIs );			try			{				rowDis = new DataInputStream( rowBis );				rowCount = IOUtil.readInt( rowDis );			}			catch ( IOException e )			{				throw new DataException( ResourceConstants.RD_LOAD_ERROR,						e,						"result data" );			}						InputStream groupIs = context.getInputStream( queryResultID,					subQueryID,					DataEngineContext.GROUP_INFO_STREAM );			BufferedInputStream groupBis = new BufferedInputStream( groupIs );			rdGroupUtil = new RDGroupUtil( groupBis,					new CacheProviderImpl( this ) );						// TODO: temp logic			if( false )				this.loadForIV( );						try			{				groupBis.close( );				groupIs.close( );			}			catch ( IOException e )			{				// ignore it			}						this.isPrepared = true;		}	}