Angular：如何将私有方法纳入代码覆盖率

typescript
import { ComponentFixture, TestBed } from '@angular/core/testing';
import { MyComponent } from './my.component';
describe('MyComponent', () => {
  let component: MyComponent;
  let fixture: ComponentFixture<MyComponent>;
  beforeEach(async () => {
    awAIt TestBed.configureTestingModule({
      declarations: [ MyComponent ]
    })
    .compileComponents();
  });
  beforeEach(() => {
    fixture = TestBed.createComponent(MyComponent);
    component = fixture.componentInstance;
    fixture.detectChanges();
  });
  it('should create', () => {
    expect(component).toBeTruthy();
  });
  it('should call the private method', () => {
    spyOn(component, 'privateMethod');
    component.publicMethod();
    expect(component.privateMethod).toHaveBeenCalled();
  });
});