### Question:
NoopOplog implements Oplog { public static NoopOplog get() { return INSTANCE; } private  NoopOplog(); static NoopOplog get(); @Override void handleInsert(String namespace, List<Document> documents); @Override void handleUpdate(String namespace, Document selector, Document query, List<Object> ids); @Override void handleDelete(String namespace, Document query, List<Object> deletedIds); @Override void handleDropCollection(String namespace); @Override Cursor createCursor(Document changeStreamDocument, String namespace, Aggregation aggregation);  }### Answer:
@Test void testSingleton() { NoopOplog oplog = NoopOplog.get(); NoopOplog oplog1 = NoopOplog.get(); assertThat(oplog).isSameAs(oplog1); }