How can I convert the below function into an arrow function.

const handler: HttpHandler = {
      handle: function (req: HttpRequest<any>): Observable<HttpEvent<any>> {
        return of({} as any);
      }
    }

const handler: HttpHandler = {
      handle: function (req: HttpRequest<any>): Observable<HttpEvent<any>> {
        return of({} as any);
      }
    }