names.add(name); }
    public String[] getPropertyNames(String prefix)    {        Set names = new HashSet();        Enumeration propNames = properties.propertyNames();        while ( propNames.hasMoreElements() ) {            String name = (String) propNames.nextElement();            if ( prefix == null || "".equals(prefix) || name.startsWith(prefix) )                names.add(name);        }        Map args = getRequestArguments();        if ( args != null ) {            Iterator keys = args.keySet().iterator();            while ( keys.hasNext() ) {                String name = (String) keys.next();                if ( names.contains(name) )                    names.remove(name);                names.add(name);            }        }        return (String[]) names.toArray(new String[0]);    }