anchor.diff:    
       _lineParent = alineParent;
       _nodes = anodes;
  +    if(_nodes == null) {
  +      _nodes = [];
  +    }
       matrixillate(matrix);
  -  
  +
       _nodes.forEach(unposition);
     
       _columns = railize(_colCount, colWidth);
  
positive.code:       if (col == 0) {
          return 96;
        }
        var node = _nodes[col - 1];
        if (node.attributes.containsKey('h-flex') || node.attributes.containsKey('flex')) {
          return -1;
  
negative.code:   bool _isLayoutJobStarted = false;  
    int _colCount = 0, _rowCount = 0;
    List<Map<int,int>> _colOwners, _rowOwners;
    List<Element> _nodes = [];
    Element _lineParent;
    List<Map<String,int>> _rows;
    List<Map<String,int>> _columns;
  