Without this you just get two pointers in the debug log.
Before:
I0627 21:48:44.136615 1 dns.go:215] Existing recordset {0xc820168830 0xc820691540} is not equal to needed recordset &{0xc820168848 0xc820686040}, removing existing and adding needed.
After:
I0627 22:26:46.221856 1 dns.go:215] Existing recordset <(clouddns) "federated-service.e2e-tests-service-cuza5.federation.svc.us-central1-c.us-central1.kube.5yetis.net." type=CNAME rrdatas=["federated-service.e2e-tests-service-cuza5.federation.svc.us-central1.kube.5yetis.net."] ttl=180>
I0627 22:26:46.221885 1 dns.go:216] ... not equal to needed recordset <(clouddns) "federated-service.e2e-tests-service-cuza5.federation.svc.us-central1-c.us-central1.kube.5yetis.net." type=CNAME rrdatas=["federated-service.e2e-tests-service-cuza5.federation.svc.us-central1.kube.5yetis.net."] ttl=180>
I0627 22:26:46.221919 1 dns.go:217] ... removing existing and adding needed.
