[JS] 데이터 n개씩 묶어주는 키 추가하기

const data = {
    time: [
      '00:00',
      '01:00',
      '02:00',
      '03:00',
      '04:00',
      '05:00',
      '06:00',
      '07:00',
      '08:00',
      '09:00',
      '10:00',
    ],
    value: [
       0.71, 0.52, 0.34, 0.25, 0.34, 0.54, 0.8, 0.77, 1.16, 2.1, 10.47,
    ]
}

const groupKeyData = {
  ...data,
  groupKey: data.time.map((item, index) => {
    return Math.floor(index / 3).toString();
  }),
};