@Test
public void testMutate() throws ExecutionException, InterruptedException {

  Put put = new Put(Bytes.toBytes("rowKey"));
  RowMutationEntry entry = RowMutationEntry.create("rowKey");
  when(mockRequestAdapter.adaptEntry(put)).thenReturn(entry);
  when(mockBulkMutation.add(entry)).thenReturn(ApiFutures.immediateFuture(null));
  asyncBufferedMutator.mutate(put).get();
  verify(mockRequestAdapter).adaptEntry(put);
  verify(mockBulkMutation).add(entry);
}