for i, want := range fiboNums {
		n := i * 10
		got := string(fibo(n).utoa(10))
		if got != want {
			t.Errorf("fibo(%d) failed: got %s want %s", n, got, want)
		}
	}
}

func BenchmarkFibo(b *testing.B) {
	for i := 0; i < b.N; i++ {
		fibo(1e0)
		fibo(1e1)
		fibo(1e2)
		fibo(1e3)
		fibo(1e4)
		fibo(1e5)
	}
}

var bitTests = []struct {
	x    string
	i    uint