anchor.diff:      this._module     = parseStackTraceToGetCurrentFileName(stackTrace),
       this._stackTrace = mapOrDefault(stackTrace, (st) => new SentryStackTrace._fromStackTrace(st));
   
  -  String toJson() => '''
  -{ 
  -  "type"      : "${this._type}",
  -  "value"     : "${this._value}",
  -  "module"    : "${this._module}",
  -  "stacktrace": ${this._stackTrace.toJson()} 
  -}''';
  +  toJson() => {
  +    "type"      : this._type,
  +    "value"     : this._value,
  +    "module"    : this._module,
  +    "stacktrace": this._stackTrace.toJson(),
  +  };
   }
   
   /**
  
positive.code:                     .map((frame) => new SentryStackFrame._fromFrame(frame))
                      .toList();
  
    String toJson() =>
      '{ "frames": [ ${this._frames.map((f) => f.toJson()).where(isNotNull).join(',')} ] }';
  }
  
  /**
  
negative.code:  */
  class SentryStackFrame {
    String _filename, _module, _function;
    int _lineno, _colno = 0;
  
    /**
     * Creates a stackframe object from a line from the stacktrace, e.g.
     *    #0      RavenClientTests._testCaptureException (file:///c:/raven-dart/src/raven_client.dart:28:7)
     */
    SentryStackFrame._fromFrame(String frame) {
      var fileStartIdx = frame.indexOf(new RegExp(r'\((file)|(package)|(dart):'));
      if (fileStartIdx >= 0) {
        this._function = parseStackTraceToGetCurrentMethodName(frame);
        this._filename = frame.substring(fileStartIdx, frame.lastIndexOf('.dart'));
        this._module   = this._filename.split('/').last;
        var lineInfo  = frame.substring(frame.lastIndexOf('.dart')+5, frame.lastIndexOf(')'));
        var linePos   = lineInfo.split(':').where(isNotNullOrEmpty).toList();
        this._lineno   = int.parse(linePos[0]);
        if (linePos.length > 1) {
          this._colno    = int.parse(linePos[1]);
        }
      }
    }
  
    _toJson() => {
      "filename": this._filename,
      "lineno"  : this._lineno,
      "colno"   : this._colno,
      "function": this._function,
      "module"  : this._module,
    };
  
    toJson() => (this._filename == null) ? null : _toJson();
  }
  
  /**
  