Currying / partial functional application

currying.service.ts

  private executeUpdate(httpHeaders: HttpHeaders, afterSuccessfulUpdate = () => {
  }) {
    this.handleError(error, httpHeaders, (callbackHttpHeaders: HttpHeaders) => {
      this.executeUpdate(callbackHttpHeaders).pipe(first()).subscribe(afterSuccessfulUpdate);
    });
  }

  private handleError(error: Error, httpHeaders: HttpHeaders, callback: Function) {
    if (error.status === 412) {
      let httpHeadersWithConfirmation = new HttpHeaders();
      for (const headerKey of httpHeaders.keys()) {
        httpHeadersWithConfirmation = httpHeadersWithConfirmation.append(headerKey, httpHeaders.get(headerKey));
      }
      httpHeadersWithConfirmation = httpHeadersWithConfirmation.append('confirmed', 'true');
      this.openErrorDialog(error, () => callback(httpHeadersWithConfirmation));
    }
  }