anchor.diff:  import 'dart:collection';
   import '../lib/redis.dart';
   
  -test_performance(){
  -  const int N = 200000;
  +Future test_performance(int n){
  +  int N = n;
     int rec=0;
     int start;
     RedisConnection conn = new RedisConnection();
     Duration zero = new Duration(seconds:0);
     return conn.connect('localhost',6379).then((Command command){
  -    print("test started, please wait ...");
       start =  new DateTime.now().millisecondsSinceEpoch;
       command.pipe_start();
       command.send_object(["SET","test","0"]);
  
positive.code:   })
    .then((_){
      //return testing_helper(test_long_running(2000000),"one by one for longer time");
    });
  
  }
  
negative.code:       double perf = N/diff;
        print("$N operations done in $diff s\nperformance $perf/s");
      });
      return r;
    });
  }
  