anchor.diff:   */
   class SentryStackFrame {
     String _filename, _module, _function;
  -  int _lineno, _colno;
  +  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('file:///');
  +    var fileStartIdx = frame.indexOf(new RegExp(r'\((file)|(package)|(dart):'));
       if (fileStartIdx >= 0) {
         this._function = parseStackTraceToGetCurrentMethodName(frame);
  -      this._filename = frame.substring(fileStartIdx+8, frame.lastIndexOf('.dart')+5);
  +      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]);
  -      this._colno    = int.parse(linePos[1]);
  +      if (linePos.length > 1) {
  +        this._colno    = int.parse(linePos[1]);
  +      }
       }
     }
   
  -  String _toJson() => '''
  -{ 
  -  "filename": "${this._filename}",
  -  "lineno"  : ${this._lineno},
  -  "colno"   : ${this._colno},
  -  "function": "${this._function}",
  -  "module"  : "${this._module}" 
  -}''';
  +  _toJson() => {
  +    "filename": this._filename,
  +    "lineno"  : this._lineno,
  +    "colno"   : this._colno,
  +    "function": this._function,
  +    "module"  : this._module,
  +  };
   
  -  String toJson() => mapOrDefault(this._filename, (_) => _toJson());
  +  toJson() => (this._filename == null) ? null : _toJson();
   }
   
   /**
  
positive.code:     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()} 
  }''';
  }
  
  /**
  
negative.code:                     .map((frame) => new SentryStackFrame._fromFrame(frame))
                      .toList();
  
    toJson() => {"frames": this._frames.map((f) => f.toJson()).where(isNotNull).toList() };
  }
  
  /**
  