@Test
public void testMutateRowAsync() {

  RowMutation rowMutation = RowMutation.create(TABLE_ID, "key");
  MutateRowRequest request = rowMutation.toProto(REQUEST_CONTEXT);
  ListenableFuture<MutateRowResponse> response =
      Futures.immediateFuture(MutateRowResponse.getDefaultInstance());
  when(client.mutateRowAsync(request)).thenReturn(response);
  clientWrapper.mutateRowAsync(rowMutation);
  verify(client).mutateRowAsync(request);
}