Is it possible to use `FieldValue.increment(_:)` on `Map` field values?

For instance, if you have a field called `foo` whose value is a `Map` type, and inside `foo` is a key-value pair `bar: Int`, can you increment `bar` without using the method in question?

A [similar question](https://stackoverflow.com/questions/56427582/how-to-use-fieldvalue-increment-on-the-property-of-an-object-type-document-fie) for JS was asked and the answer was to use `FieldValue.increment(_:)` using the dot notation, like one would use for JS `Object` types; e.g. `points.total`. I've tried this on iOS, but instead of incrementing `bar`, it creates a field `foo.bar` of `Number`.

If possible, it would be great to know how.