getQuote() {
  this.errorMessage = '';
  this.quote = this.twainService.getQuote().pipe(
    startWith('...'),
    catchError( (err: any) => {
      // Wait a turn because errorMessage already set once this turn
      setTimeout(() => this.errorMessage = err.message || err.toString());
      return of('...'); // reset message to placeholder
    })
  );