anchor.diff:  
       final Map<String, dynamic> meshJson = list[0]["meshes"][0];
       final Map<String, dynamic> animJson = list[0]["animations"][0];
  -    skeleton = ImportSkeletonFromAssimp2Json(list[0]);
  +    VM.Matrix4 globalOffsetTransform = new VM.Matrix4.identity();
  +    List<Bone> skeleton = ImportSkeletonFromAssimp2Json(list[0]);
       final GeometryBuilder gb =
           ImportGeometryFromAssimp2JsonMesh(meshJson, skeleton);
  -    anim = ImportAnimationFromAssimp2Json(animJson, skeleton);
  +    SkeletalAnimation anim = ImportAnimationFromAssimp2Json(animJson, skeleton);
       print("Imnported ${anim}");
       {
         MeshData md = GeometryBuilderToMeshData(meshFile, chronosGL, gb);
  
positive.code: 
  final double kAnimTimeStep = 0.0333;
  
  void main() {
    StatsFps fps =
        new StatsFps(HTML.document.getElementById("stats"), "blue", "gray");
  
negative.code:       animationSteps.add(t);
      }
  
      {
        Float32List animationData = CreateAnimationTable(
            skeleton, globalOffsetTransform, anim, animationSteps);
  