docs: public void setRawFragment(char[] escapedFragment) throws URIException {
          if (escapedFragment == null || escapedFragment.length == 0) {
              _fragment = escapedFragment;
              hash = 0;
              return;
          }
          if (!validate(escapedFragment, fragment)) {
              throw new URIException(URIException.ESCAPING,
                      "escaped fragment not valid");
          }
          _fragment = escapedFragment;
          hash = 0;
      }