def central_smoothing(proba, gamma=1e-4):
    """
    Central smoothing as shown in Malinin et al., 2020
    :param proba: Tensor containing the class probability outputs.
    :param gamma: Gamma value to use for smoothing
    :return: Output tensor after central smoothing
    """

    return (1 - gamma) * proba + gamma * 1 / (proba.shape[1])