anchor.diff:  |                                                          |
   | Log plugin for Dart.                                     |
   |                                                          |
  -| LastModified: Mar 6, 2019                                |
  +| LastModified: Mar 10, 2019                               |
   | Author: Ma Bingyao <andot@hprose.com>                    |
   |                                                          |
   \*________________________________________________________*/
  
positive.code:     if (!enabled) return next(name, args, context);
      var a = '';
      try {
        a = json.encode((args.length > 0 && args.last is Context)
            ? args.sublist(0, args.length - 1)
            : args);
      } catch (e) {
        print(e);
      }
      final result = next(name, args, context);
      result
          .then((value) => print(
              '${name}(${a.substring(1, a.length - 1)}) = ${json.encode(value)}'))
          .catchError(print);
  
negative.code:       print(e);
      }
      final response = next(request, context);
      await response.then((value) => print(utf8.decode(value))).catchError(print);
      return response;
    }
  
  