Wish you had some immutability in Javascript? Now you can!
var t = {a: 1, b: 2}.immutable();
console.log(t.a, t.b);
try {
t.a = 3; // -> Uncaught Error: a is immutable and cannot be modified.
} catch (e) {
console.log(e);
}
var t2 = t.copy({a: 3});