docs: public String[] getValueNames() {
          if (!_iSession.isValid())
              throw new IllegalStateException();
          Enumeration enumeration = this.getAttributeNames();
          Vector valueNames = new Vector();
          String name = null;
          while (enumeration.hasMoreElements()) {
              name = (String) enumeration.nextElement();
              valueNames.add(name);
          }
          String[] names = new String[valueNames.size()];
          return (String[]) valueNames.toArray(names);
      }