map function for objects instead of arrays

Question

I have an object:

myObject = { 'a': 1, 'b': 2, 'c': 3 }

I'm trying to find a native method that works like Array.prototype. The following is a map that would be used:

newObject = myObject.map(function (value, label) {
    return value * value;
});

// newObject is now { 'a': 1, 'b': 4, 'c': 9 }

Does JavaScript have a similar object map function? (I don't care about cross-browser compatibility because I want this for Node.JS.)