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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def reset_counters(self):
 """ Resets all counters, truth and classification masks. """

        self.truth_masks = None
        self.classification_masks = None
        self.pixel_truth_counts = None
        self.pixel_classification_counts = None
        self.pixel_truth_sum = None
        self.pixel_classification_sum = None
        self.val_df = None
        self.n_validation_sets = 0