}
}

func messWith(fileName string, corrupter func(b []byte)) (r io.ReaderAt, size int64) {
	data, err := os.ReadFile(filepath.Join("testdata", fileName))
	if err != nil {
		panic("Error reading " + fileName + ": " + err.Error())
	}
	corrupter(data)
	return bytes.NewReader(data), int64(len(data))
}

func returnCorruptCRC32Zip() (r io.ReaderAt, size int64) {

				b.Run(fmt.Sprintf("%d", j), func(b *testing.B) {
					b.ReportAllocs()
					b.SetBytes(int64(j))
					data := sd.data[:j]
					for i := 0; i < b.N; i++ {
						Fields(data)
					}
				})
			}
		})
	}
}

func BenchmarkFieldsFunc(b *testing.B) {
	for _, sd := range bytesdata {
		b.Run(sd.name, func(b *testing.B) {
			for j := 1 << 4; j <= 1<<20; j <<= 4 {