### Question:
DatabaseFactory { public static DatabaseFactory getInstance() { if (instance == null) { instance = new DatabaseFactory(); } return instance; } protected  DatabaseFactory(); static DatabaseFactory getInstance(); static void reset(); List<Database> getImplementedDatabases(); void register(Database database); Database findCorrectDatabaseImplementation(DatabaseConnection connection); String findDefaultDriver(String url); void clearRegistry();  }### Answer:
@Test public void getInstance() { assertNotNull(DatabaseFactory.getInstance()); }