Is it possible to generate type adaptors without annotating the type in question?

**Question**
If I don't have rights to modify and add annotations to a class I want to store using Hive, or if I would just rather not strongly couple it to the Hive library, is it still possible to use `hive_generate` to generate TypeAdapators automatically?

Although I suspect it must be, I can't find any documentation which suggests this is possible, all examples I can find assume the type is annotated with `@HiveType()` etc. first.

If it is not currently possible, how hard would it be to adapt `hive_generate` to achieve this?

**Version**
- Platform: all
- Flutter version: any
- Hive version: any