public static CachedDateTimeZone forZone(DateTimeZone zone){
  if (zone instanceof CachedDateTimeZone) {
    return (CachedDateTimeZone)zone;
  }
  return new CachedDateTimeZone(zone);
}

public static CachedDateTimeZone forZone ( DateTimeZone zone ) { if ( zone instanceof CachedDateTimeZone ) { return ( CachedDateTimeZone ) zone ; } return new CachedDateTimeZone ( zone ) ; }
returns a new cacheddatetimezone unless given zone is already cached .
