private static Object jsConstructor(Context cx, Scriptable scope, 
                                        Scriptable thisObj, Object[] args)
    {
        if (args.length == 0 || args[0] == null || 
            args[0] == Undefined.instance)
        {
            throw ScriptRuntime.typeError1("msg.no.properties", 
                                           ScriptRuntime.toString(args[0]));
        }
        Scriptable obj = ScriptRuntime.toObject(scope, args[0]);
        boolean keyOnly = args.length > 1 && ScriptRuntime.toBoolean(args[1]);
        if (thisObj != null) {
            // Called as a function. Convert to iterator if possible.
          
            // For objects that implement java.lang.Iterable or
            // java.util.Iterator, have JavaScript Iterator call the underlying
            // iteration methods
            Iterator<?> iterator = 
                VMBridge.instance.getJavaIterator(cx, scope, obj);
            if (iterator != null) {
                scope = ScriptableObject.getTopLevelScope(scope);
                return cx.getWrapFactory().wrap(cx, scope,
                        new WrappedJavaIterator(iterator, scope),
                        WrappedJavaIterator.class);
            }
            
            // Otherwise, just call the runtime routine
            Scriptable jsIterator = ScriptRuntime.toIterator(cx, scope, obj, 
                                                             keyOnly);
            if (jsIterator != null) {
                return jsIterator;
            }
        }
        
        // Otherwise, just set up to iterate over the properties of the object.
        // Do not call __iterator__ method.
        Object objectIterator = ScriptRuntime.enumInit(obj, cx,
            keyOnly ? ScriptRuntime.ENUMERATE_KEYS_NO_ITERATOR
                    : ScriptRuntime.ENUMERATE_ARRAY_NO_ITERATOR);
        ScriptRuntime.setEnumNumbers(objectIterator, true);
        NativeIterator result = new NativeIterator(objectIterator);
        result.setPrototype(NativeIterator.getClassPrototype(scope, 
                                result.getClassName()));
        result.setParentScope(scope);
        return result;
    }