var thingy = (function(){
    var a = 42;
    var b = 23;
    var c = 84;
    var d = 13;
    var e = 90;
    var f = 34;
    var g = 52;
    return {
        foo: function() {
            return a + b + c + d + e + f + g;
        },
        bar: function() {
            a = 1;
            b = 2;
            c = 3;
            d = 4;
            e = 5;
            f = 6;
            g = 7;
        }
    };
})();

for (var i = 0; i < 10000000; ++i) {
    var result = thingy.foo();
    if (result != 42 + 23 + 84 + 13 + 90 + 34 + 52)
        throw "Error: bad result: " + result;
}

thingy.bar();
var result = thingy.foo();
if (result != 1 + 2 + 3 + 4 + 5 + 6 + 7)
    throw "Error: bad result: " + result;