code: @Nonnull
    public CalendarIntervalScheduleBuilder withIntervalInHours (final int intervalInHours)
    {
      _validateInterval (intervalInHours);
      m_nInterval = intervalInHours;
      m_eIntervalUnit = EIntervalUnit.HOUR;
      return this;
    }
docs: Specify an interval in the IntervalUnit.HOUR that the produced Trigger will
  repeat at.
  
  @param intervalInHours
  the number of hours at which the trigger should repeat.
  @return the updated CalendarIntervalScheduleBuilder
  @see ICalendarIntervalTrigger#getRepeatInterval()
  @see ICalendarIntervalTrigger#getRepeatIntervalUnit()