seek method
Reset the internal pointer to a specific offset depending on the SeekOrigin.
Implementation
void seek(int offset, SeekOrigin origin) {
switch (origin) {
case SeekOrigin.begin:
_index = offset;
break;
case SeekOrigin.current:
_index += offset;
break;
case SeekOrigin.end:
_index = _byteData.lengthInBytes - offset;
break;
}
}