Return the examples in the dataset in order, sorted, or shuffled.

def data(self):
        """Return the examples in the dataset in order, sorted, or shuffled."""
        if self.sort:
            xs = sorted(self.dataset, key=self.sort_key)
        elif self.shuffle:
            xs = [self.dataset[i] for i in self.random_shuffler(range(len(self.dataset)))]
        else:
            xs = self.dataset
        return xs