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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 read_dataset(args, dataset):
 """ Read dataset from tokenized files. """

    path = os.path.join(vars(args)[dataset])
    logger.info('reading data from {}'.format(path))
    examples = [line.strip().split('\t') for line in open(path)]
    if args.max_num_examples > 0:
        examples = examples[:args.max_num_examples]
    # NOTE: assume data has been tokenized
    dataset = gluon.data.SimpleDataset([(e[0], e[1], LABEL_TO_IDX[e[2]]) for e in examples])
    dataset = dataset.transform(lambda s1, s2, label: (
        ['NULL'] + s1.lower().split(),
        ['NULL'] + s2.lower().split(), label),
                                lazy=False)
    logger.info('read {} examples'.format(len(dataset)))
    return dataset