Return correct command based on the family, e.g. ipv4 or ipv6

def _iptables_cmd(family='ipv4'):
    '''
    Return correct command based on the family, e.g. ipv4 or ipv6
    '''
    if family == 'ipv6':
        return salt.utils.path.which('ip6tables')
    else:
        return salt.utils.path.which('iptables')