我在Angular 8中使用xlsx和FileSaver包生成了Excel工作表，但现在我面临一个问题：-我希望标题行突出显示并加粗。请帮助我。

代码：-

import { Injectable } from '@angular/core';
import * as FileSaver from 'file-saver';
import * as XLSX from 'xlsx';
const EXCEL_TYPE = 'application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;charset=UTF-8';
const EXCEL_EXTENSION = '.xlsx';

@Injectable({
  providedIn: 'root'
})
export class ExcelReportService {

  constructor() { }

  public exportAsExcelFile(json: any[],excelFileName: string): void {
    const worksheet: XLSX.WorkSheet = XLSX.utils.json_to_sheet(json);
    const workbook: XLSX.WorkBook = { Sheets: { 'data': worksheet },SheetNames: ['data'] };
    const excelBuffer: any = XLSX.write(workbook,{ bookType: 'xlsx',type: 'array' });
    this.saveAsExcelFile(excelBuffer,excelFileName);
  }
  private saveAsExcelFile(buffer: any,fileName: string): void {
    const data: Blob = new Blob([buffer],{ type: EXCEL_TYPE });
    FileSaver.saveAs(data,fileName+ EXCEL_EXTENSION);
  }
}