Source:
<code>LuceneChangeIndex( @GerritServerConfig Config cfg, SitePaths sitePaths, @IndexExecutor(INTERACTIVE) ListeningExecutorService executor, Provider<ReviewDb> db, ChangeData.Factory changeDataFactory, FillArgs fillArgs, @Assisted Schema<ChangeData> schema, @Assisted @Nullable String base) throws IOException { this.sitePaths = sitePaths; this.fillArgs = fillArgs; this.executor = executor; this.db = db; this.changeDataFactory = changeDataFactory; this.schema = schema; Version luceneVersion = checkNotNull( LUCENE_VERSIONS.get(schema), "unknown Lucene version for index schema: %s", schema); CustomMappingAnalyzer analyzer = new CustomMappingAnalyzer(new StandardAnalyzer(CharArraySet.EMPTY_SET), CUSTOM_CHAR_MAPPING); queryBuilder = new QueryBuilder(analyzer); BooleanQuery.setMaxClauseCount(cfg.getInt("index", "defaultMaxClauseCount", BooleanQuery.getMaxClauseCount())); GerritIndexWriterConfig openConfig = new GerritIndexWriterConfig(luceneVersion, cfg, "changes_open"); GerritIndexWriterConfig closedConfig = new GerritIndexWriterConfig(luceneVersion, cfg, "changes_closed"); if (cfg.getBoolean("index", "lucene", "testInmemory", false)) { <START> dir = null; <END> openIndex = new SubIndex(new RAMDirectory(), "ramOpen", openConfig); closedIndex = new SubIndex(new RAMDirectory(), "ramClosed", closedConfig); } else { if (base == null) { dir = LuceneVersionManager.getDir(sitePaths, schema); } else { dir = Paths.get(base); } openIndex = new SubIndex(dir.resolve(CHANGES_OPEN), openConfig); closedIndex = new SubIndex(dir.resolve(CHANGES_CLOSED), closedConfig); } }</code><technical_language>obvious me, set null in this case</technical_language>

Target:
LuceneChangeIndex( @GerritServerConfig Config cfg, SitePaths sitePaths, @IndexExecutor(INTERACTIVE) ListeningExecutorService executor, Provider<ReviewDb> db, ChangeData.Factory changeDataFactory, FillArgs fillArgs, @Assisted Schema<ChangeData> schema, @Assisted @Nullable String base) throws IOException { this.sitePaths = sitePaths; this.fillArgs = fillArgs; this.executor = executor; this.db = db; this.changeDataFactory = changeDataFactory; this.schema = schema; Version luceneVersion = checkNotNull( LUCENE_VERSIONS.get(schema), "unknown Lucene version for index schema: %s", schema); CustomMappingAnalyzer analyzer = new CustomMappingAnalyzer(new StandardAnalyzer(CharArraySet.EMPTY_SET), CUSTOM_CHAR_MAPPING); queryBuilder = new QueryBuilder(analyzer); BooleanQuery.setMaxClauseCount(cfg.getInt("index", "defaultMaxClauseCount", BooleanQuery.getMaxClauseCount())); GerritIndexWriterConfig openConfig = new GerritIndexWriterConfig(luceneVersion, cfg, "changes_open"); GerritIndexWriterConfig closedConfig = new GerritIndexWriterConfig(luceneVersion, cfg, "changes_closed"); if (cfg.getBoolean("index", "lucene", "testInmemory", false)) { openIndex = new SubIndex(new RAMDirectory(), "ramOpen", openConfig); closedIndex = new SubIndex(new RAMDirectory(), "ramClosed", closedConfig); } else { Path dir = base != null ? Paths.get(base) : LuceneVersionManager.getDir(sitePaths, schema); openIndex = new SubIndex(dir.resolve(CHANGES_OPEN), openConfig); closedIndex = new SubIndex(dir.resolve(CHANGES_CLOSED), closedConfig); } }