@Test
public void testTransaction() {

  byte[] key = new byte[]{};
  Transaction jedisTransaction = mock(Transaction.class);
  when(jedis.multi()).thenReturn(jedisTransaction);
  TransactionRunner<?> transaction = mock(TransactionRunner.class);
  rf.transaction(key, transaction);
  verify(jedis).multi();
  verify(transaction).run(any(RedisFacade.TransactionFacade.class));
  verify(jedisTransaction).exec();
}