var mylib;

(function() {
    var variable1 = null;
    var variable2 = null;
    var variable3 = null;
    //...

    window.mylib = {
        func1: function() {

        },
        func2: function() {

        },
        func3: function() {

        }
        //...
    };

    function privateFunc1() {
        //...
    }

    function privateFunc2() {
        //...
    }
    function privateFunc3() {
        //...
    }

    addEventListener("storage", mylib.callEventListener);
    addEventListener("unload", mylib.callEventListener);
})();