query params handler. made for underscore

QueryParams

(function (lib) {
    "use strict";
    var QueryParams = function (initParams) {

        var params = initParams || {};
        function addParam(key, value) {
            params[key] = value;
        }
        function toString() {
            return _.map(params, function (value, key) {
                return key + "=" + encodeURIComponent(value);
            }).join("&");
        }

        return (function () {
            return {
                "add": addParam,
                "get": toString
            };
        }());
    };
    lib.mixin({"QueryParams": QueryParams});
}(_));