def __init__(self):
        """
        Creates an instance of the standalone Forgetting metric
        """

        self.initial: Dict[int, float] = dict()
        """
        The initial value for each key.
        """

        self.last: Dict[int, float] = dict()
        """
        The last value detected for each key
        """

        Creates an instance of the standalone Forgetting metric
        
avalanche/evaluation/metrics/forgetting_bwt.py