def METHOD_NAME(self, ddns_fqdn):
    host, ip = ddns_fqdn, '1.2.3.4'
    remove_records(host)
    # first add with this IP, should work without issue:
    add(host, ip)
    assert query_ns(host, 'A') == ip
    different_ip = '4.3.2.1'
    # trying to add again with same IP should raise
    add(host, different_ip)  # internally triggers an update
    assert query_ns(host, 'A') == different_ip