it('should return the correct values for TBT', () => {
      expect(getVitalsScore('TBT', 100)).toEqual('good');
      expect(getVitalsScore('TBT', 200)).toEqual('good');
      expect(getVitalsScore('TBT', 201)).toEqual('needsImprovement');
      expect(getVitalsScore('TBT', 700)).toEqual('poor');