anchor.diff:    /// Creates a new XmlTagException for a missing closing tag.
     factory XmlTagException.missingClosingTag(String name) =>
         XmlTagException('Missing closing tag </$name>.');
  +
  +  @override
  +  String toString() => 'XmlTagException: $message';
   }
  
positive.code: 
    /// Creates a new XmlParentException.
    XmlParentException(String message) : super(message);
  }
  
  /// Exception thrown when the end tag does not match the open tag.
  
negative.code:   int? get offset => position;
  
    @override
    String toString() => 'XmlParserException: $message at $line:$column';
  }
  
  /// Exception thrown when an unsupported node type is used.
  