code: public String formatISO(
          IsoDateStyle dateStyle,
          IsoDecimalStyle decimalStyle,
          ClockUnit precision,
          ZonalOffset offset,
          InfinityStyle infinityStyle
      ) {
  
          MomentInterval interval = this.toCanonical();
          StringBuilder buffer = new StringBuilder(65);
          ChronoPrinter<Moment> printer = Iso8601Format.ofMoment(dateStyle, decimalStyle, precision, offset);
          if (interval.getStart().isInfinite()) {
              buffer.append(infinityStyle.displayPast(printer, Moment.axis()));
          } else {
              printer.print(interval.getStartAsMoment(), buffer);
          }
          buffer.append('/');
          if (interval.getEnd().isInfinite()) {
              buffer.append(infinityStyle.displayFuture(printer, Moment.axis()));
          } else {
              printer.print(interval.getEndAsMoment(), buffer);
          }
          return buffer.toString();
  
      }
docs: /*[deutsch]
  <p>Formatiert die kanonische Form dieses Intervalls im angegebenen ISO-8601-Stil. </p>
  
  @param   dateStyle       iso-compatible date style
  @param   decimalStyle    iso-compatible decimal style
  @param   precision       controls the precision of output format with constant length
  @param   offset          timezone offset
  @param   infinityStyle   controlling the format of infinite boundaries
  @return  String
  @throws  IllegalStateException   if there is no canonical form
  or given infinity style prevents infinite intervals
  @see     #toCanonical()
  @since   4.18