From this import you should create two type of entities which are related:
- User (with user_id and username)
- UserRole (with 'name')
The given json should create 2 roles and 1 user object, and relate those 2 roles to the user.
In the microflow that handles this import, check if a given role is already known in your application (through database retrieve) and otherwise, create the role. If the role is already known, only add the assocation to the new user.