anchor.diff: -library webgl2;
  +library wgl2;
   
   
   import "dart:html";
  
positive.code: 
  void _initVertexBuffer()
  {
    
  }
  
  
negative.code: wgl.Buffer posBuffer;
  wgl.Buffer normalBuffer;
  wgl.Buffer texcoordBuffer;
  
  // index buffer
  wgl.Buffer indexBuffer;
  
  void init()
  {
    glCanvas = document.querySelector("#drawArea");
  