if ( dataSources == null )  return;
	public void shutdown()	{		// Close all open data sources		Collection col = dataSources.values();		Iterator it = col.iterator();		while (it.hasNext())		{			DataSourceRuntime ds = (DataSourceRuntime)it.next();			try			{				closeDataSource( ds );			}			catch ( DataException e )			{				// TODO: log exception here				e.printStackTrace();			}		}				sharedScope = null;		dataSetDesigns = null;		dataSources = null;		compiler = null;	}