How to use the iview/src/utils/assist.deepCopy function in iview

makeColumns () {
                let columns = deepCopy(this.columns);
                let left = [];
                let right = [];
                let center = [];

                columns.forEach((column, index) => {
                    column._index = index;
                    column._columnKey = columnKey++;
                    column._width = column.width ? column.width : '';    // update in handleResize()
                    column._sortType = 'normal';
                    column._filterVisible = false;
                    column._isFiltered = false;
                    column._filterChecked = [];

                    if ('filterMultiple' in column) {
                        column._filterMultiple = column.filterMultiple;
                    } else {

return {
                ready: false,
                tableWidth: 0,
                columnsWidth: {},
                prefixCls: prefixCls,
                compiledUids: [],
                objData: this.makeObjData(),     // checkbox or highlight-row
                rebuildData: [],    // for sort or filter
                cloneColumns: this.makeColumns(),
                showSlotHeader: true,
                showSlotFooter: true,
                bodyHeight: 0,
                bodyRealHeight: 0,
                scrollBarWidth: getScrollBarSize(),
                currentContext: this.context,
                cloneData: deepCopy(this.data),    // when Cell has a button to delete row data, clickCurrentRow will throw an error, so clone a data
                isShowResizeBorder:false,
                fixedTableStyle: {},
                fixedRightTableStyle: {}
            };
        },
        computed: {

this.data.forEach((row, index) => {
                    const newRow = deepCopy(row);// todo 直接替换
                    newRow._isHover = false;
                    if (newRow._disabled) {
                        newRow._isDisabled = newRow._disabled;
                    } else {
                        newRow._isDisabled = false;
                    }
                    if (newRow._checked) {
                        newRow._isChecked = newRow._checked;
                    } else {
                        newRow._isChecked = false;
                    }
                    if (newRow._expanded) {
                        newRow._isExpanded = newRow._expanded;
                    } else {
                        newRow._isExpanded = false;
                    }

setTimeout(() => {
                        this.cloneData = deepCopy(this.data);
                    }, 0);
                },

makeData () {
                let data = deepCopy(this.data);
                data.forEach((row, index) => {
                    row._index = index;
                    row._rowKey = rowKey++;
                });
                return data;
            },
            makeDataWithSort () {