anchor.diff:              case "/dir2/line.dat":
                   return _makeLine(webpath, displayName);
               case "/newcube.dat":
  -                return _makeNewCube(webpath, displayName);
  +                return _makeRandom(webpath, displayName);
               case "/oldcube.dat":
  -                return _makeOldCube(webpath, displayName);
  +                return _makeRandom(webpath, displayName);
               case "/dir1/random.dat":
                   return _makeRandom(webpath, displayName);
               case "/terrain1.dat":
  
positive.code: 
          return cloud;
      }
  
  
      static PointCloud _makeTerrain(int which, String webpath, String displayName) {
          _Terrain terrain = new _Terrain(which);
  
negative.code:         throw new RialtoArgumentError("invalid file name");
      }
  
      static PointCloud _makeRandom(String webpath, String displayName) {
          Map<String, Float32List> map = new Map();
  
          var numPoints = 3;
  
          var positionsX = new Float32List(numPoints);
          var positionsY = new Float32List(numPoints);
  