old IE shim for creating empty dict objects

dict-ie.js

// pre-ES5 IE version
var dict = (function() {
    var PROPERTY_KEYS = [
        "hasOwnProperty",
        "isPrototypeOf",
        "propertyIsEnumerable"
        "valueOf",
        "toString",
        "toLocaleString",
        "constructor"
    ];
    var frame = document.createElement("iframe");

    document.body.appendChild(frame);
    var proto = frame.contentWindow.Object.prototype;
    document.body.removeChild(frame);

    for (var i = 0, n = PROPERTY_KEYS.length; i < n; i++) {
        delete proto[PROPERTY_KEYS[i]];
    }
    function Dict() { }
    Dict.prototype = proto;
    function dict() {
        return new Dict();
    }
    return dict;
})();

"propertyIsEnumerable",