anchor.diff:  
     Tag(this.key, this.value);
   
  -  String toJson() => '[ "${this.key}", "${this.value}" ]';
  +  toJson() => [this.key, this.value];
   }
   
   /**
  
positive.code:                     .map((frame) => new SentryStackFrame._fromFrame(frame))
                      .toList();
  
    String toJson() =>
      '{ "frames": [ ${this._frames.map((f) => f.toJson()).where(isNotNull).join(',')} ] }';
  }
  
  /**
  
negative.code:     this.modules    = defaultArg(modules, {}),
      this.exception  = mapOrDefault(exception, (exn) => new SentryException._fromException(exn, stackTrace.toString()));
  
    String toJson() => JSON.encode({
      "event_id"    : this.eventId,
      "message"     : this.message,
      "timestamp"   : this.timestamp.millisecondsSinceEpoch,
      "level"       : this.logLevel.toJson(),
      "logger"      : this.logger,
      "platform"    : this.platform,
      "culprit"     : this.culprit,
      "tags"        : this.tags.map((tag) => tag.toJson()).toList(),
      "extra"       : this.extra,
      "server_name" : this.serverName,
      "modules"     : this.modules,
      "exception"   : [(this.exception == null) ? '' : this.exception.toJson()],
    });
  }