docs: public String getTimeUnitAbbreviation() {
      switch (timeUnit) {
        case DAYS:
          return "day";
        case HOURS:
          return "hr";
        case MICROSECONDS:
          return "\u00B5s";
        case MILLISECONDS:
          return "ms";
        case MINUTES:
          return "min";
        case NANOSECONDS:
          return "ns";
        case SECONDS:
          return "s";
        default:
          return "unkwn";
      }
    }