anchor.diff:        var a = new Sample();
         var b = new Sample();
         
  -      expect(a).toBe(a);
  -      expect(a).not.toBe(b);
  +      expect(a).toBe(a);     // a === a is true
  +      expect(a).not.toBe(b); // a === b is false
       });
       
       it("not is valid.", (){
  
positive.code:       var a = new Sample();
        var b = new Sample();
        
        expect(a).toEqual(a);
        expect(a).toEqual(b);
      });
  
      describe("child", (){
  
negative.code:     });
    
      it("failure...", (){
        expect(1).toBe(2); // this test is fail.
      });
    
      it("toBe is valid.", (){
  