func TestMinAndMax(t *testing.T) {
	values := []int{0, 456, 123, 789, -123} // elt 0 => empty set
	wantMax := []int{intsets.MinInt, 456, 456, 789, 789}
	wantMin := []int{intsets.MaxInt, 456, 123, 123, -123}

	var set intsets.Sparse
	for i, x := range values {
		if i != 0 {
			set.Insert(x)
		}
		if got, want := set.Min(), wantMin[i]; got != want {
			t.Errorf("Min #%d: got %d, want %d", i, got, want)
		}
		if got, want := set.Max(), wantMax[i]; got != want {
			t.Errorf("Max #%d: got %d, want %d", i, got, want)
		}
	}

	set.Insert(intsets.MinInt)
	if got, want := set.Min(), intsets.MinInt; got != want {
		t.Errorf("Min: got %d, want %d", got, want)
	}

	set.Insert(intsets.MaxInt)
	if got, want := set.Max(), intsets.MaxInt; got != want {
		t.Errorf("Max: got %d, want %d", got, want)
	}
}