code: private String[] toStrings(Locale l) {
          String v = ISO639_MAP.get(l.getLanguage());
          if (v==null)
              return new String[]{'_'+l.toString()};
          else
              return new String[]{'_'+l.toString(),
                                  '_'+v+l.toString().substring(2)};
      }
docs: Some language codes have changed over time, such as Hebrew from iw to he.
  This method returns all such variations in an array.
  
  @see Locale#getLanguage()