javascript - Jasmine spy created in it() not called while the call happend in beforeEach() - why? -

the following taken jasmine expected spy have been called . specs fine last one, 1 added, why "expected spy setyear have been called." in codepen? doesn't "setyear" called?

class dataservice {    constructor () {    this.setyear(2017);  }  setyear (year)  {     this._selectedyear =year;  } }  describe("dataservice", () => {     let service= dataservice;     beforeeach(function () {         service = new dataservice();     });      it("should initialize shared data service", () => {        var spy = spyon(service, "setyear").and.callthrough();         expect(service).tobedefined();         // expect(spy);         expect(service._selectedyear).toequal(2017);     });     it("should call setyear",()=>{         var spy = spyon(service, "setyear").and.callthrough();;         expect(service.setyear).tohavebeencalled();     });  });