retryWhen()

const tableDefined$ = new Observable((observer) => {
 
      if (!this.table || this.table._columns === undefined) {
        observer.error('Table not defined.');
      } else if (this.table._columns.length > 0) {
        observer.next(this.table._columns);
        observer.complete();
      }
    });
 
    tableDefined$.pipe(retryWhen(concatMap((err, index) => (index < 14 ? timer(300) : throwError(err))))).subscribe(() => {
      this.setCustomColWidth();
    });