Generate extension classes from IG

I am currently using the fhir-codegen to generate the vallue sets frome the [FrCore Project](https://simplifier.net/frenchprofiledfhirar).

I would like to know if it would be possible to generate the classes that represents the extension. From what i've read, i've understood that for the moment it is not possible to generate classes for the profiles according to their structure definition, but what about the extensions and the slices (for example the Identifiers for [Patient](https://simplifier.net/frenchprofiledfhirar/FRCorePatientProfile/~overview) ) ? It would make me avoid to write the extensions classes manually and generate them from the tool..

Thank's for reading and for your attention !