anchor.diff:  is_quiet(?RDECRQ) -> true;
   is_quiet(_) -> false.
   
  +% -------------------------------------------------
  +
  +noop_test() ->
  +    {ok, Sock} = gen_tcp:connect("localhost", 11211,
  +                                 [binary, {packet, 0}, {active, false}]),
  +    {ok, _H, _E} = cmd(?NOOP, Sock, nil, #mc_entry{}),
  +    ok = gen_tcp:close(Sock).
  +
  
positive.code:     end,
      case Opcode =:= RecvHeader#mc_header.opcode of
          true  -> S = RecvHeader#mc_header.statusOrReserved,
                   case S = ?SUCCESS of
                       true  -> {ok, RecvHeader, RecvEntry};
                       false -> {error, RecvHeader, RecvEntry}
                   end;
  
negative.code:     end.
  
  cmd_binary_quiet(Opcode, Sock, _RecvCallback, Entry) ->
      ok = send(Sock, req, #mc_header{opcode = Opcode}, Entry).
  
  cmd_binary_vocal(Opcode, Sock, RecvCallback, Entry) ->
      ok = send(Sock, req, #mc_header{opcode = Opcode}, Entry),
      cmd_binary_vocal_recv(Opcode, Sock, RecvCallback, Entry).
  
  cmd_binary_vocal_recv(Opcode, Sock, RecvCallback, Entry) ->
  