anchor.diff:  part of orange;
   
   
  -abstract class Scene {
  +class Scene {
     static int FOGMODE_NONE = 0;
     static int FOGMODE_EXP = 1;
     static int FOGMODE_EXP2 = 2;
  
positive.code:       _lights.add(node);
      }
      nodes.add(node);
      if (node.name == null) {
        node.name = "Node${nodes.length}";
      }
    }
  
  
negative.code:     _transparentMeshes.clear();
    }
  
    void enter() {
      
    }
  
    // TODO remove parameters
    void enterFrame(num elapsed, num interval) {
  
    }
  