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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_index(group, version='1.1'):
 """Return the index stored in a h5features group. :param h5py.Group group: The group to read the index from. :param str version: The h5features version of the `group`. :return: a 1D numpy array of features indices. """

    if version == '0.1':
        return np.int64(group['index'][...])
    elif version == '1.0':
        return group['file_index'][...]
    else:
        return group['index'][...]