code: public static WstxInputSource constructCharArraySource
          (WstxInputSource parent, String fromEntity,
           char[] text, int offset, int len, Location loc, URL src)
      {
      	SystemId sysId = SystemId.construct(loc.getSystemId(), src);
          return new CharArraySource(parent, fromEntity, text, offset, len, loc, sysId);
      }
docs: Factory method usually used to expand internal parsed entities; in
  which case context remains mostly the same.