### Question:
LuceneIndexer extends DocumentIndexer { public static synchronized LuceneIndexer getInstance(String lucDirPath) { if (indexer == null && lucDirPath != null) { indexer = new LuceneIndexer(lucDirPath); } return indexer; } private  LuceneIndexer(String lucDirPath); static synchronized LuceneIndexer getInstance(String lucDirPath); @Override final void index(EntityMetadata metadata, final MetamodelImpl metaModel, Object object); @Override final void unindex(EntityMetadata metadata, Object id, KunderaMetadata kunderaMetadata, Class<?> parentClazz); @Override final void update(EntityMetadata metadata, final MetamodelImpl metaModel, Object entity, Object id,
            String parentId); void prepareEmbeddedId(TopDocs docs, Map<String, Object> indexCol, IndexSearcher searcher,
            EntityMetadata metadata, MetamodelImpl metaModel); @Override final Map<String, Object> search(String luceneQuery, int start, int count, boolean fetchRelation,
            KunderaMetadata kunderaMetadata, EntityMetadata metadata); void indexDocument(EntityMetadata metadata, Document document); void updateDocument(String id, Document document, String EmbeddedEntityFieldName); void close(); @Override void flush(); @Override void index(EntityMetadata metadata, final MetamodelImpl metaModel, Object object, String parentId,
            Class<?> clazz); @Override boolean entityExistsInIndex(Class<?> entityClass, KunderaMetadata kunderaMetadata, EntityMetadata metadata); @Override boolean documentExistsInIndex(EntityMetadata metadata, Object id, KunderaMetadata kunderaMetadata,
            boolean isEmbeddedId, Class<?> parentClazz); @Override void index(Class entityClazz, EntityMetadata entityMetadata, Map<String, Object> values, Object parentId,
            final Class parentClazz); @Override void unIndex(Class entityClazz, Object entity, EntityMetadata metadata, MetamodelImpl metamodel); @Override Map<String, Object> search(Class<?> clazz, EntityMetadata m, String luceneQuery, int start, int end); @Override Map<String, Object> search(KunderaMetadata kunderaMetadata, KunderaQuery kunderaQuery,
            PersistenceDelegator persistenceDelegator, EntityMetadata m, int firstResult, int maxResults);  }### Answer:
@Test public void testGetInstance() { LuceneIndexer indexer = LuceneIndexer.getInstance(LUCENE_DIR_PATH); Assert.assertNotNull(indexer); indexer.close(); }