def METHOD_NAME(self, blk, data):
    if blk.id != 0:
        # CODING_SCHEME RS applied only for all blocks except BLK0.
        coded_bytes = 12
        data.pos = coded_bytes * 8
        plain_data = data.readlist("32*uint:8")[::-1]
        # takes 32 bytes
        # apply RS encoding
        rs = reedsolo.RSCodec(coded_bytes)
        # 32 byte of data + 12 bytes RS
        calc_encoded_data = list(rs.encode([x for x in plain_data]))
        data.pos = 0
        if calc_encoded_data != data.readlist("44*uint:8")[::-1]:
            raise FatalError("Error in coding scheme data")
        data = data[coded_bytes * 8 :]
    if blk.len < 8:
        data = data[(8 - blk.len) * 32 :]
    return data