Bug 182061 Data engine changes to support result set sharing
data/org.eclipse.birt.data/src/org/eclipse/birt/data/engine/impl/DataEngineImpl.java
* Get the DataEngineSession instance bound to this DataEngineImpl.
	 * 
	 * @return
	 */
	public DataEngineSession getSession( )
	{
		return session;
	}
	
	/*
	 * @see org.eclipse.birt.data.engine.api.DataEngine#shutdown()
	 */
	public void shutdown( )
	{
		logger.entering( "DataEngineImpl", "shutdown" );
		if ( dataSources == null )
		{
			
			logger.fine( "The data engine has already been shutdown" );
			return;
		}
		
		Collection col = dataSources.values( );
		Iterator it = col.iterator( );
		while ( it.hasNext( ) )
		{
			DataSourceRuntime ds = (DataSourceRuntime) it.next( );
			try
			{
				closeDataSource( ds );