func BenchmarkIterate(b *testing.B) {
	var tree llrb.Tree
	for i := 0; i < len(fixture.TestData); i++ {
		tree.Insert(llrbItemUnique(fixture.TestData[i]))
	}
	b.ResetTimer()

	for i := 0; i < b.N; i++ {
		tree.Do(func(i llrb.Comparable) bool {
			_ = i.(llrbItemUnique).Key
			_ = i.(llrbItemUnique).Value
			return false
		})
	}
}