def _get_base_qual(pread):
    """
    Returns: (seq, (quals))

    Used flags:
        indel
            indel length for the position following the current pileup site.
            This quantity peeks ahead to the next cigar operation in this
            alignment. If the next operation is an insertion, indel will
            be positive. If the next operation is a deletion, it will be
            negation. 0 if the next operation is not an indel.
        is_del
            1 iff the base on the padded read is a deletion
    """
    if pread.is_del:
        return '-', ()
    qpos = pread.query_position
    aln = pread.alignment
    if pread.indel > 0:
        sl = slice(qpos, qpos + pread.indel + 1)
        return aln.query_sequence[sl], tuple(aln.query_qualities[sl])
    return aln.query_sequence[qpos], (aln.query_qualities[qpos],)
