function update(object, path, updater) {
      return object == null ? object : baseUpdate(object, path, castFunction(updater));
    }
This method is like `_.set` except that accepts `updater` to produce the
value to set. Use `_.updateWith` to customize `path` creation. The `updater`
is invoked with one argument: (value).

**Note:** This method mutates `object`.

@static
@memberOf _
@since 4.6.0
@category Object
@param {Object} object The object to modify.
@param {Array|string} path The path of the property to set.
@param {Function} updater The function to produce the updated value.
@returns {Object} Returns `object`.
@example

var object = { 'a': [{ 'b': { 'c': 3 } }] };

_.update(object, 'a[0].b.c', function(n) { return n * n; });
console.log(object.a[0].b.c);
// => 9

_.update(object, 'x[0].y.z', function(n) { return n ? n + 1 : 0; });
console.log(object.x[0].y.z);
// => 0