code: private static TimeUnit getDurationUnits(Integer value)
     {
        TimeUnit result = null;
  
        if (value != null)
        {
           int index = value.intValue();
           if (index >= 0 && index < DURATION_UNITS.length)
           {
              result = DURATION_UNITS[index];
           }
        }
  
        if (result == null)
        {
           result = TimeUnit.DAYS;
        }
  
        return (result);
     }
docs: Maps a duration unit value from a recurring task record in an MPX file
  to a TimeUnit instance. Defaults to days if any problems are encountered.
  
  @param value integer duration units value
  @return TimeUnit instance