anchor.diff:    List<int> indices = new List<int>();
     String mtllib;
   
  -  void trimTable(String url) {
  +  int trimTable(String url) {
       // remove empty objects from _partTable
       /*
       List<String> emptyList = new List<String>(); // create a copy to avoid concurrent modifications
  
positive.code: 
      //print("Obj.fromString: url=$url: lines=${lines.length}");
  
      trimTable(url); // remove empty objects from _partTable
  
      // FIXME
      int textCoordNeeded = indexCounter * 2;
  
negative.code:     });
      emptyList.forEach((String name) => _partTable.remove(name)); // remove selected keys
      */
      
      int deleteCount = 0;
  
      _partTable.keys.where((name) {
        // where: filter keys
        bool empty = _partTable[name].indexListSize < 1;
        if (empty) {
          ++deleteCount;
          //print("OBJ: deleting empty object=$name loaded from url=$url");
        }
        return empty;
  