How to import from ngx-bootstrap in unit test?

I am working on an angular application and I want to write a test for a component (using jest). In the component I am using tooltip from ngx-bootstrap, but I am unable to import TooltipModule in the test. Here is the test that I wrote: if I comment the import, the test passes.

beforeEach(() => {
    TestBed.configureTestingModule({
        declarations: [MyComponent],
        imports: [TooltipModule.forRoot(), FormsModule],
        providers: [
            {
                provide: ElementRef,
                useClass: MockElementRef
            },
            ChangeDetectorRef
        ]
    }).compileComponents();

    fixture = TestBed.createComponent(MyComponent);
    component = fixture.componentInstance;
});

it('should create a component', () => {
    expect(component).toBeTruthy();
});

});

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Source Url How to import from ngx-bootstrap in unit test?