keras/src/models/model.py/Model/__init__
class Model:    def __init__(self, *args, **kwargs):
        Trainer.__init__(self)
        from keras.src.models import functional

        # Signature detection for usage of a `Model` subclass
        # as a `Functional` subclass
        if functional_init_arguments(args, kwargs):
            inject_functional_model_class(self.__class__)
            functional.Functional.__init__(self, *args, **kwargs)
        else:
            Layer.__init__(self, *args, **kwargs)