keras/src/ops/nn.py/MultiHot/__init__
class MultiHot:    def __init__(
        self, num_classes=None, axis=-1, dtype=None, sparse=False, **kwargs
    ):
        if num_classes is None and "num_tokens" in kwargs:
            num_classes = kwargs.pop("num_tokens")
        if num_classes is None:
            raise ValueError("Argument `num_classes` must be specified.")
        super().__init__(**kwargs)
        self.num_classes = num_classes
        self.axis = axis
        self.dtype = dtype or backend.floatx()
        self.sparse = sparse