keras/src/layers/activations/leaky_relu.py/LeakyReLU/__init__
class LeakyReLU:    def __init__(self, negative_slope=0.3, **kwargs):
        if "alpha" in kwargs:
            negative_slope = kwargs.pop("alpha")
            warnings.warn(
                "Argument `alpha` is deprecated. "
                "Use `negative_slope` instead."
            )
        super().__init__(**kwargs)
        if negative_slope is None or negative_slope < 0:
            raise ValueError(
                "The negative_slope value of a Leaky ReLU layer "
                "cannot be None or negative value. Expected a float."
                f" Received: negative_slope={negative_slope}"
            )
        self.supports_masking = True
        self.negative_slope = negative_slope