code: public String[] getValueNames() {
  
          Enumeration enumeration = super.getAttributeNames();
          Vector valueNames = new Vector();
          String name = null;
          boolean securityPropFound = false;
          while (enumeration.hasMoreElements()) {
              name = (String) enumeration.nextElement();
              if (!name.equals(SECURITY_PROP_NAME)) {
                  valueNames.add(name);
              } else {
                  securityPropFound = true;
              }
          }
          _hasSecurityInfo = securityPropFound;
          String[] names = new String[valueNames.size()];
          return (String[]) valueNames.toArray(names);
      }
docs: /*
  @see javax.servlet.http.HttpSession#getValueNames()