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

        By default this metric in its initial state will return an accuracy
        value of 0. The metric can be updated by using the `update` method
        while the running accuracy can be retrieved using the `result` method.
        """
        self._mean_accuracy = Mean()
        """The mean utility that will be used to store the running accuracy."""
Creates an instance of the standalone Accuracy metric.

        By default this metric in its initial state will return an accuracy
        value of 0. The metric can be updated by using the `update` method
        while the running accuracy can be retrieved using the `result` method.
        
avalanche/evaluation/metrics/accuracy.py