How to create sub-flow in Java | KC 12.0

Hi
We use Keycloak 12.0.4
I need to create flow with sub-flow and condition in Java
I see createFlow and addExecution functions but I do not understand how to create sub-flow
Anyone managed to do some like this?

Hey @allegro did you find any method to create a sub flow in an existing flow or while adding a new flow?