### Question:
CSVRepository implements Repository { @Override public CheckpointCloseableIterable<ApiOperation> getIds(byte[] checkpoint) throws RepositoryException { return null; } CSVRepository(); @Override void init(RepositoryContext repositoryContext); @Override CheckpointCloseableIterable<ApiOperation> getIds(byte[] checkpoint); @Override CheckpointCloseableIterable<ApiOperation> getChanges(byte[] checkpoint); @Override ApiOperation getDoc(Item item); @Override boolean exists(Item item); @Override void close(); @Override CheckpointCloseableIterable<ApiOperation> getAllDocs(byte[] checkpoint);  }### Answer:
@Test public void getIds_returnsNull() throws Exception { CSVRepository csvRepository = new CSVRepository(); assertNull(csvRepository.getIds(null)); }