Ag-grid case insensitive sorting

ag-grid.ts

{
  headerName: this.utilsService.setColumnHeader('first_name', this.headerName),
  field: 'name',
  resizable: true,
  sortable: true,
  filter: true,
  sortingOrder: ['asc', 'desc'],
  width: 160,
  comparator: (valueA, valueB, nodeA, nodeB, isInverted) => {
    return this.caseInsensitiveSort(valueA, valueB, nodeA, nodeB, isInverted); }
},
        
 caseInsensitiveSort(valueA, valueB, nodeA, nodeB, isInverted) {
    return valueA.toLowerCase().localeCompare(valueB.toLowerCase());
 }