Retrieve start and end for a VCF record, skips BNDs without END coords

def _get_start_end(parts, index=7):
    """Retrieve start and end for a VCF record, skips BNDs without END coords
    """
    start = parts[1]
    end = [x.split("=")[-1] for x in parts[index].split(";") if x.startswith("END=")]
    if end:
        end = end[0]
        return start, end
    return None, None