serialization_fields = [field for field in fields if field.mode == "serialization"]
    flat_validation_models = get_flat_models_from_fields(
        validation_fields, known_models=set()
    )
    flat_serialization_models = get_flat_models_from_fields(
        serialization_fields, known_models=set()
    )
    flat_validation_model_fields = [
        ModelField(