anchor.diff:  
   typedef void field_parser(String field, String param, String line, int lineNum, String url);
   
  -Map<String, Material> mtllib_parse(String str, String url, { printUnknownFields: true }) {
  +Map<String, Material> mtllib_parse(String str, String url, {printUnknownFields: true}) {
   
     Map<String, Material> lib = new Map<String, Material>();
     Material currMaterial;
  
positive.code:     */
    }
  
    Obj.fromString(String url, String str, {bool printStats: false, bool debugPrintParts: false, String defaultName: null, bool debugPrintTrace: false}) {
  
      Map<String, int> indexTable = new Map<String, int>();
      List<double> _vertCoord = new List<double>();
  
negative.code:     field_parser parser = parserTable[field];
      if (parser == null) {
        if (printUnknownFields) {
          print("mtllib_parse: unknown field=[$field] on line=$lineNum from url=$url: [$line]");
        }
        return;
      }
  