Bug 208419 NullPointerException at CubeResultSet close
engine/org.eclipse.birt.report.engine/src/org/eclipse/birt/report/engine/data/dte/DataInteractiveEngine.java
private String loadResultSetID( IBaseResultSet parentResult, String queryID )
			throws BirtException
	{
		String resultSetID = null;
		if ( parentResult == null )
		{
			
			
			if ( context.isExecutingMasterPage( ) )
			{
				long pageNumber = context.getPageNumber( );
				resultSetID = getResultID( null, String.valueOf( pageNumber ),
						queryID );
				if ( resultSetID == null )
				{
					resultSetID = getResultID( null, "-1", queryID );
				}
			}
			else
			{
				resultSetID = getResultID( null, "-1", queryID );
			}
		}
		else
		{
			String pRsetId;
			if ( parentResult instanceof QueryResultSet )
			{
				pRsetId = ( (QueryResultSet) parentResult )