def binarize_worker(document):
    """Binarizes a BOW document.

    Parameters
    ----------
    document : list of (int, float)
        A document.

    Returns
    -------
    binarized_document : list of (int, float)
        The binarized document.
    """

    binarized_document = [(term_id, 1) for term_id, _ in document]
    return binarized_document