Adds dynamic properties to an object.
function addProps(obj) {
        var rest = [];
        for (var _i = 1; _i < arguments.length; _i++) {
            rest[_i - 1] = arguments[_i];
        }
        for (var i = 0, n = rest.length; i < n; i += 2) {
            if (illa.isString(rest[i])) {
                obj[rest[i]] = rest[i + 1];
            }
        }
        return obj;
    }