keras/src/layers/layer.py/Layer/_check_super_called
class Layer:    def _check_super_called(self):
        if getattr(self, "_lock", True):
            raise RuntimeError(
                f"In layer '{self.__class__.__name__}', you forgot to call "
                "`super().__init__()` as the first statement "
                "in the `__init__()` method. Go add it!"
            )