keras/src/layers/preprocessing/feature_space.py/Cross/__init__
class Cross:    def __init__(self, feature_names, crossing_dim, output_mode="one_hot"):
        if output_mode not in {"int", "one_hot"}:
            raise ValueError(
                "Invalid value for argument `output_mode`. "
                "Expected one of {'int', 'one_hot'}. "
                f"Received: output_mode={output_mode}"
            )
        self.feature_names = tuple(feature_names)
        self.crossing_dim = crossing_dim
        self.output_mode = output_mode