t.Error("Unexpected record set")
				}
			},
		},
	}

	for _, tc := range tests {
		t.Run(tc.name, tc.f)
	}

}

func TestNullMX(t *testing.T) {
	fake := fakeDNSServer{
		rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) {
			r := dnsmessage.Message{
				Header: dnsmessage.Header{