properties.setProperty( Index.PropertyKeys.PAYLOADCLASS, payload.getClass().getName() );
if ( field != null ) properties.setProperty( Index.PropertyKeys.FIELD, field );
properties.save( batchBasename + DiskBasedIndex.PROPERTIES_EXTENSION );
// We *must* generate a fake term file, or index combination won't work.
final PrintWriter termWriter = new PrintWriter( new FileWriter( batchBasename + DiskBasedIndex.TERMS_EXTENSION ) );
termWriter.println( "#" );
termWriter.close();
cutPoints.add( cutPoints.getInt( cutPoints.size() - 1 ) + documentCount );
accumulatorStream.reset();