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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 load_vocab(vocab_file):
 """Loads a vocabulary file into a dictionary."""

    vocab = collections.OrderedDict()
    index = 0
    with io.open(vocab_file, 'r') as reader:
        while True:
            token = reader.readline()
            if not token:
                break
            token = token.strip()
            vocab[token] = index
            index += 1
    return vocab