def __init__(
        self,
        alpha: float = 0.2,
        beta: float = 1.0,
        skip_labels: Union[int, List[int]] = -1,
    ):
        """
        Margin loss constructor.

        Args:
            alpha: alpha
            beta: beta
            skip_labels (int or List[int]): labels to skip
        """
        super().__init__()
        self.alpha = alpha
        self.beta = beta
        self.skip_labels = skip_labels

        Margin loss constructor.

        Args:
            alpha: alpha
            beta: beta
            skip_labels (int or List[int]): labels to skip
        
catalyst/contrib/losses/margin.py