How to use the @nebular/theme/components/cdk/overlay/overlay-position.NbAdjustment.HORIZONTAL function in @nebular/theme

it('should map left position to start', () => {
    const withPositionsSpy = spyOn(strategy, 'withPositions').and.callThrough();

    strategy.position(NbPosition.LEFT).adjustment(NbAdjustment.HORIZONTAL);

    const overlayService: NbOverlayService = TestBed.get(NbOverlayService);
    const overlayRef = overlayService.create({ positionStrategy: strategy });
    overlayRef.attach(new NbComponentPortal(PortalComponent));

    expect(withPositionsSpy).toHaveBeenCalledWith(jasmine.objectContaining([
      { originX: 'start', originY: 'center', overlayX: 'end', overlayY: 'center', offsetX: -15 },
      { originX: 'end', originY: 'center', overlayX: 'start', overlayY: 'center', offsetX: 15 },
    ]));
  });

it('should map right position to end', () => {
    const withPositionsSpy = spyOn(strategy, 'withPositions').and.callThrough();

    strategy.position(NbPosition.RIGHT).adjustment(NbAdjustment.HORIZONTAL);

    const overlayService: NbOverlayService = TestBed.get(NbOverlayService);
    const overlayRef = overlayService.create({ positionStrategy: strategy });
    overlayRef.attach(new NbComponentPortal(PortalComponent));

    expect(withPositionsSpy).toHaveBeenCalledWith(jasmine.objectContaining([
      { originX: 'end', originY: 'center', overlayX: 'start', overlayY: 'center', offsetX: 15 },
      { originX: 'start', originY: 'center', overlayX: 'end', overlayY: 'center', offsetX: -15 },
    ]));
  });
});