`@Frozen` does not work on Map type

The ```@Frozen``` annotation does not work to freeze a full Map, like so:
```
@Frozen Map<String, String> map;
```
It generate the following CQL:
```
map<text, text>
```
Instead of:
```
frozen<map<text, text>>
```

It work on List and Set, or to froze the key and value of the Map, but not to froze the full Map.

I tested this on version 3.2.2.