processBytes method
Process len bytes from inp starting at offset inpOff and output the
result to out at offset outOff.
Returns the number of bytes written to the output.
Implementation
@override
int processBytes(
Uint8List inp, int inpOff, int len, Uint8List out, int outOff) {
data.write(inp, inpOff, len);
return 0;
}