int dns_answer_contains(DnsAnswer *a, DnsResourceKey *key);
int dns_answer_find_soa(DnsAnswer *a, DnsResourceKey *key, DnsResourceRecord **ret);
+DnsAnswer *dns_answer_merge(DnsAnswer *a, DnsAnswer *b);
+
DEFINE_TRIVIAL_CLEANUP_FUNC(DnsAnswer*, dns_answer_unref);