want := "\x80\x81"
		if !empty {
			want = "\x80Hi\x81"
		}

		if got != want {
			t.Errorf("empty=%t: got %q, want %q", empty, got, want)
		}
	}
}

func BenchmarkEncoder(b *testing.B) {
	buf, err := os.ReadFile("../testdata/e.txt")
	if err != nil {
		b.Fatal(err)
	}
	if len(buf) == 0 {
		b.Fatalf("test file has no data")
	}

	for e := 4; e <= 6; e++ {