### Question:
RangeStoreServiceImpl implements RangeStoreService, AutoCloseable { @Override public CompletableFuture<GetNamespaceResponse> getNamespace(GetNamespaceRequest request) { return rootRange.getNamespace(request); } RangeStoreServiceImpl(long scId,
                          StorageContainerPlacementPolicy rangePlacementPolicy,
                          OrderedScheduler scheduler,
                          MVCCStoreFactory storeFactory,
                          StorageServerClientManager clientManager);   RangeStoreServiceImpl(long scId,
                          OrderedScheduler scheduler,
                          MVCCStoreFactory storeFactory,
                          RootRangeStoreFactory rrStoreFactory,
                          MetaRangeStoreFactory mrStoreFactory,
                          TableStoreFactory tableStoreFactory); long getId(); @Override CompletableFuture<Void> start(); @Override CompletableFuture<Void> stop(); @Override void close(); @Override CompletableFuture<CreateNamespaceResponse> createNamespace(CreateNamespaceRequest request); @Override CompletableFuture<DeleteNamespaceResponse> deleteNamespace(DeleteNamespaceRequest request); @Override CompletableFuture<GetNamespaceResponse> getNamespace(GetNamespaceRequest request); @Override CompletableFuture<CreateStreamResponse> createStream(CreateStreamRequest request); @Override CompletableFuture<DeleteStreamResponse> deleteStream(DeleteStreamRequest request); @Override CompletableFuture<GetStreamResponse> getStream(GetStreamRequest request); @Override CompletableFuture<GetActiveRangesResponse> getActiveRanges(GetActiveRangesRequest request); @Override CompletableFuture<RangeResponse> range(RangeRequest request); @Override CompletableFuture<PutResponse> put(PutRequest request); @Override CompletableFuture<DeleteRangeResponse> delete(DeleteRangeRequest request); @Override CompletableFuture<TxnResponse> txn(TxnRequest request); @Override CompletableFuture<IncrementResponse> incr(IncrementRequest request);  }### Answer:
@Test public void testGetNamespace() throws Exception { mockStorageContainer(SCID); GetNamespaceResponse expectedResp = GetNamespaceResponse.getDefaultInstance(); when(rrStore.getNamespace(any(GetNamespaceRequest.class))) .thenReturn(FutureUtils.value(expectedResp)); GetNamespaceRequest expectedReq = GetNamespaceRequest.getDefaultInstance(); assertSame( expectedResp, FutureUtils.result(rrStore.getNamespace(expectedReq))); verify(rrStore, times(1)) .getNamespace(same(expectedReq)); }