{responseCode: "00", responseMsg: "ok",…}
msgInfo: {msgId: 1256, category: "G", title: "test", titleYn: "Y", type: "S", sendUserSeq: 10651,…}
attachmentYn: "N"
category: "G"
content: [{resSeq: 1816, resType: "T", resUrl: "", resContent: "test", resSize: 4, resResolution: null,…}]
fileAllow: "GUC100"
msgId: 1256
msgType: "U"
receiveName: ""
regDate: "2020-09-18 11:11:13"
reservationTime: null
sendUserName: "테스트4"
sendUserSeq: 10651
sendYn: "Y"
smsYn: "N"
title: "test"
titleYn: "Y"
type: "S"
recvList: [{userSeq: 4892, userName: "노희석", cancelYn: "N", readDate: null, readYn: "N"},…]
0: {userSeq: 4892, userName: "노희석", cancelYn: "N", readDate: null, readYn: "N"}
1: {userSeq: 4951, userName: "박남신", cancelYn: "N", readDate: null, readYn: "N"}
2: {userSeq: 6377, userName: "양호중", cancelYn: "N", readDate: null, readYn: "N"}
3: {userSeq: 6891, userName: "정지용", cancelYn: "N", readDate: null, readYn: "N"}
4: {userSeq: 8966, userName: "강혜숙", cancelYn: "N", readDate: null, readYn: "N"}
5: {userSeq: 9283, userName: "조정훈", cancelYn: "N", readDate: null, readYn: "N"}
6: {userSeq: 10363, userName: "IC센터", cancelYn: "N", readDate: null, readYn: "N"}
7: {userSeq: 10648, userName: "테스트1", cancelYn: "N", readDate: null, readYn: "N"}
8: {userSeq: 10649, userName: "테스트2", cancelYn: "N", readDate: null, readYn: "N"}
9: {userSeq: 10650, userName: "테스트3", cancelYn: "N", readDate: null, readYn: "N"}


for (const item of groupList) {
  const nodeType = item.division;
  const node: GroupNode = {
    nodeType,
    children: []
  };

  item.groupList.sort((a, b) =>
    a.registDate < b.registDate ? 1 : a.registDate > b.registDate ? -1 : 0
  );

  item.groupList.forEach((groupInfo) => {
    node.children.push({
      nodeType,
      groupInfo
    });
  });

  if (!!this.nodeMap.get(item.division)) {
    this.nodeMap.get(item.division)[0].children = node.children;
  } else {
    this.nodeMap.set(item.division, [node]);
  }
}

// deleted filtering.
this.nodeMap = new Map(
  [...this.nodeMap.entries()].filter(
    (map) => list.findIndex((item) => item.division === map[0]) > -1
  )
);

// sorting.
this.nodeMap = new Map(
  [...this.nodeMap.entries()].sort((a, b) =>
    b[0] > a[0] ? 1 : b[0] < a[0] ? -1 : 0
  )
);

{
    "statusCode": 200,
    "errorMessage": "",
    "data": {
        "links": [
            {
                "rel": "self",
                "href": "http://127.0.0.1:9095/api/v1.0/call/history?callDvCd=in&page=0&size=10&sort=createdDt,desc"
            }
        ],
        "content": [
            {
                "callingNum": "01071116902",
                "rcvNum": "07082774004",
                "callDvCd": "in",
                "callTypCd": "DOD",
                "callStTime": "2020-09-24T18:50:36+0900",
                "callEdTime": "2020-09-24T18:52:08+0900",
                "totalCallTime": "85",
                "callStsCd": "00",
                "callKindCd": 0,
                "contactInfo": {
                    "name": "홍길동_1",
                    "position": "차장",
                    "bookmark": 0,
                    "blacklist": 0,
                    "links": [
                        {
                            "rel": "self",
                            "href": "http://127.0.0.1:9095/api/v1.0/contact/6"
                        }
                    ]
                },
                "id": 39,
                "links": [
                    {
                        "rel": "self",
                        "href": "http://127.0.0.1:9095/api/v1.0/call/history/39"
                    }
                ]
            },
            {
                "callingNum": "01071116902",
                "rcvNum": "07082774004",
                "callDvCd": "in",
                "callTypCd": "DOD",
                "callStTime": "2020-09-24T18:37:40+0900",
                "callEdTime": "2020-09-24T18:46:50+0900",
                "totalCallTime": "0",
                "callStsCd": "02",
                "callKindCd": 0,
                "contactInfo": {
                    "name": "홍길동_1",
                    "position": "차장",
                    "bookmark": 0,
                    "blacklist": 0,
                    "links": [
                        {
                            "rel": "self",
                            "href": "http://127.0.0.1:9095/api/v1.0/contact/6"
                        }
                    ]
                },
                "id": 38,
                "links": [
                    {
                        "rel": "self",
                        "href": "http://127.0.0.1:9095/api/v1.0/call/history/38"
                    }
                ]
            },
            {
                "callingNum": "01071116902",
                "rcvNum": "07082774004",
                "callDvCd": "in",
                "callTypCd": "DOD",
                "callStTime": "2020-09-24T18:33:21+0900",
                "callEdTime": "2020-09-24T18:34:32+0900",
                "totalCallTime": "47",
                "callStsCd": "00",
                "callKindCd": 0,
                "contactInfo": {
                    "name": "홍길동_1",
                    "position": "차장",
                    "bookmark": 0,
                    "blacklist": 0,
                    "links": [
                        {
                            "rel": "self",
                            "href": "http://127.0.0.1:9095/api/v1.0/contact/6"
                        }
                    ]
                },
                "id": 36,
                "links": [
                    {
                        "rel": "self",
                        "href": "http://127.0.0.1:9095/api/v1.0/call/history/36"
                    }
                ]
            },
            {
                "callingNum": "01071116902",
                "rcvNum": "07082774004",
                "callDvCd": "in",
                "callTypCd": "DOD",
                "callStTime": "2020-09-24T18:21:28+0900",
                "callEdTime": "2020-09-24T18:22:25+0900",
                "totalCallTime": "36",
                "callStsCd": "00",
                "callKindCd": 0,
                "contactInfo": {
                    "name": "홍길동_1",
                    "position": "차장",
                    "bookmark": 0,
                    "blacklist": 0,
                    "links": [
                        {
                            "rel": "self",
                            "href": "http://127.0.0.1:9095/api/v1.0/contact/6"
                        }
                    ]
                },
                "id": 35,
                "links": [
                    {
                        "rel": "self",
                        "href": "http://127.0.0.1:9095/api/v1.0/call/history/35"
                    }
                ]
            },
            {
                "callingNum": "01071116902",
                "rcvNum": "07082774004",
                "callDvCd": "in",
                "callTypCd": "DOD",
                "callStTime": "2020-09-24T18:18:23+0900",
                "callEdTime": "2020-09-24T18:19:04+0900",
                "totalCallTime": "0",
                "callStsCd": "02",
                "callKindCd": 0,
                "contactInfo": {
                    "name": "홍길동_1",
                    "position": "차장",
                    "bookmark": 0,
                    "blacklist": 0,
                    "links": [
                        {
                            "rel": "self",
                            "href": "http://127.0.0.1:9095/api/v1.0/contact/6"
                        }
                    ]
                },
                "id": 34,
                "links": [
                    {
                        "rel": "self",
                        "href": "http://127.0.0.1:9095/api/v1.0/call/history/34"
                    }
                ]
            }
        ],
        "page": {
            "size": 10,
            "totalElements": 5,
            "totalPages": 1,
            "number": 0
        }
    }
}