def _filter(self) -> None:
        """Filter MNIST dataset: select images of 5, 6, 7, 8, 9 classes."""
        mask = self._mnist.targets >= self._split
        self._mnist.data = self._mnist.data[mask]
        self._mnist.targets = self._mnist.targets[mask]
Filter MNIST dataset: select images of 5, 6, 7, 8, 9 classes.
catalyst/contrib/datasets/mnist.py