}
	for _, c := range cases {
		if key := ToStringKey(c.values...); key != c.key {
			t.Errorf("%v: expected %v, got %v", c.values, c.key, key)
		}
	}
}

func TestContains(t *testing.T) {
	containsTests := []struct {
		name  string
		elems []string
		elem  string
		out   bool
	}{
		{"exists", []string{"1", "2", "3"}, "1", true},