got := AppendPortIfNeeded(testCases[i].addr, testCases[i].port)
		if testCases[i].expect != got {
			t.Errorf("case %s: expected %v, got %v", testCases[i].name, testCases[i].expect, got)
		}
	}
}

func TestMapIPsByIPFamily(t *testing.T) {
	testCases := []struct {
		desc            string
		ipString        []string
		wantIPv6        bool
		expectCorrect   []string
		expectIncorrect []string
	}{
		{