How to use the @taquito/http-utils.HttpBackend function in @taquito/http-utils

constructor(
    private url: string = defaultIndexerUrl,
    private httpBackend: HttpBackend = new HttpBackend()
  ) {}

  constructor(private pkh: string, private rootUrl: string, private http = new HttpBackend()) {}

constructor(
    private url: string = defaultRPC,
    private chain: string = defaultChain,
    private httpBackend: HttpBackend = new HttpBackend()
  ) {}