Angular單元測試遇到的錯誤消息：Uncaught Error - Cannot find module tslib

我的單元測試源代碼：

@Component({
  selector: 'cx-host',
  template: ` <div id="a" [cxFocus]="{ autofocus: true, refreshFocus: model.uid }"></div>`,
  changeDetection: ChangeDetectionStrategy.Default,
})
class MockComponent {
  model = "";
}
      

将下圖import的代碼改成：

from '@angular/core'