def _split_gaps_from_pairs(ref_seq, seq):
    """cuts out pairs ("-", "-") from zipped
    reference and read sequences
    """
    pairs_ref_and_seq = list(zip(ref_seq, seq))
    pairs_gaps_cut = []
    for i in pairs_ref_and_seq:
        if i[0] == '-' and i[1] == '-':
            continue
        else:
            pairs_gaps_cut.append(i)
    return pairs_gaps_cut
