final String batchBasename = batchBasename( 0, basename, batchDir );
LOGGER.debug( "Generating empty index " + batchBasename );
final IndexWriter indexWriter = new BitStreamIndexWriter( batchBasename, 0, true, flags );
indexWriter.close();
final Properties properties = indexWriter.properties();
properties.setProperty( Index.PropertyKeys.SIZE, 0 );
properties.setProperty( Index.PropertyKeys.OCCURRENCES, -1 );
properties.setProperty( Index.PropertyKeys.MAXCOUNT, -1 );
properties.setProperty( Index.PropertyKeys.MAXDOCSIZE, -1 );
properties.setProperty( Index.PropertyKeys.TERMPROCESSOR, NullTermProcessor.class.getName() );