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');