### Question:
DataSourceRepositoryHolder { public static DataSourceRepositoryHolder getInstance() { return DATA_SOURCE_REPOSITORY_HOLDER; } private  DataSourceRepositoryHolder(); static DataSourceRepositoryHolder getInstance(); void init(DataSourceInformationRepository repository, Properties properties); DataSourceInformationRepository getDataSourceInformationRepository(); boolean isInitialized(); DataSourceRepositoryManager getDataSourceRepositoryManager(); RepositoryBasedDataSourceFinder getRepositoryBasedDataSourceFinder();  }### Answer:
@Test public void testGetInstance() { Assert.assertNotNull("must return an instance", DataSourceRepositoryHolder.getInstance()); }