code: private void initializeData(ULocale locale)
      {
          String key = locale.toString();
          DateIntervalInfo dii = DIICACHE.get(key);
          if ( dii == null ) {
              // initialize data from scratch
              setup(locale);
              // Marking fIntervalPatterns read-only makes cloning cheaper.
              fIntervalPatternsReadOnly = true;
              // We freeze what goes in the cache without freezing this object.
              DIICACHE.put(key, ((DateIntervalInfo) clone()).freeze());
          } else {
              initializeFromReadOnlyPatterns(dii);
          }
      }
docs: /*
  Initialize the DateIntervalInfo from locale
  @param locale   the given locale.