code: static BasicTimeZone getFrozenICUTimeZone(String id, boolean trySystem) {
          BasicTimeZone result = null;
          if (trySystem) {
              result = ZoneMeta.getSystemTimeZone(id);
          }
          if (result == null) {
              result = ZoneMeta.getCustomTimeZone(id);
          }
          return result;
      }
docs: Returns a frozen ICU type TimeZone object given a time zone ID.
  @param id the time zone ID
  @param trySystem if true tries the system time zones first otherwise skip to the
  custom time zones.
  @return the frozen ICU TimeZone or null if one could not be created.