anchor.diff:      Reply = mc_client_binary:flush(State#state.sock),
       {reply, Reply, State};
   
  -handle_call({delete, Key, VBucket}, _From, State) ->
  +handle_call({delete, Key, VBucket, CAS}, _From, State) ->
       Reply = mc_client_binary:cmd(?DELETE, State#state.sock, undefined, undefined,
                                    {#mc_header{vbucket = VBucket},
  -                                  #mc_entry{key = Key}}),
  +                                  #mc_entry{key = Key, cas = CAS}}),
       {reply, Reply, State};
   
   handle_call({set, Key, VBucket, Val}, _From, State) ->
  
positive.code: 
  
  %% @doc send a set command to memcached instance
  -spec delete(bucket_name(), binary(), integer()) ->
      {ok, #mc_header{}, #mc_entry{}, any()}.
  delete(Bucket, Key, VBucket) ->
      gen_server:call({server(Bucket, data), node()}, {delete, Key, VBucket}, ?TIMEOUT).
  
  
  %% @doc send a set command to memcached instance
  
negative.code:          flush/1,
           set/4,
           ready_nodes/4,
           sync/4, add/4, get/3, delete/3, delete/4,
           get_meta/3,
           set_with_meta/5, set_with_meta/6, set_with_meta/8,
           add_with_meta/5, add_with_meta/7]).
  