public Map 
	decodeStream(
		BufferedInputStream data )  

		throws IOException 
	{
		Object	res = decodeInputStream(new BDecoderInputStreamStream(data), 0);

		if ( res == null ){

			throw( new BEncodingException( "BDecoder: zero length file" ));

		}else if ( !(res instanceof Map )){

			throw( new BEncodingException( "BDecoder: top level isn't a Map" ));
		}

		return((Map)res );
	}