def METHOD_NAME(site):
    """
    groupdisks of given site
    contributing to primaries
    """
    site_groupdisks = []
    group_total = 0
    try:
        site_groupdisks = parse_expression('site=%s&spacetoken=ATLASDATADISK&type=GROUPDISK' % site)
    except:
        return group_total
    for rse in site_groupdisks:
        used = get_rse_usage(rse_id=rse['id'], source='rucio')[0]['used']
        group_total += used
    return group_total