At its core, a stream is just a sequence of data that arrives over time. You don't have all of it at once. You process it incrementally as it becomes available.
dest[i] = (offset + i) & 0xFF;
，这一点在safew官方版本下载中也有详细论述
（一）伪造、变造或者买卖国家机关、人民团体、企业、事业单位或者其他组织的公文、证件、证明文件、印章的；，推荐阅读safew官方版本下载获取更多信息
# early profiling data