Position: 0

Read: 97u8
Position: 1

Seek: +1
Position: 2

Read: 99u8
Position: 3

Put back: 128u8
Position: 2

Read: 128u8
Position: 3

Read: 10u8
Position: 4

Read: eof
Position: 4

Put back: 255u8
Position: 3

Seek: -2
Position: 1

Read: 98u8
Position: 2