anchor.diff:  
       neighbors.addAll(this._getSides(node, onlyWalkable));
       if (this.diagonalMovement != DiagonalMovement.Never) {
  -      neighbors.addAll(this._getCorners(node, onlyWalkable));
  +      neighbors.addAll(this._getCorners(node, onlyWalkable, diagonalMovement));
       }
   
       return neighbors;
  
positive.code:     return n1.location.distanceTo(n2.location);
    }
  
    /// Returns a list of all the nodes that are part of this graph.
    List<PointNode> get allNodes {
      List<PointNode> nodes = new List<PointNode>();
  
negative.code:     return nodes;
    }
  
    //------------------------//
    // Implementation Methods // 
    //------------------------//
  
    /// Returns whether or not this [Grid] contains a [PointNode] at [point].
    bool containsPoint(Point point) {
      return point.x >= 0 && point.y >= 0 && point.x < this.cols && point.y < this.rows;
    }
  