问题现象如下：

1. 执行命令
nc -l 19999
请求:http://localhost:19999/
得到结果如下：
GET / HTTP/1.1
Host: localhost:19999
Connection: keep-alive
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.167 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8,sq;q=0.7
Cookie: OTTER_WEBX_JSESSIONID0=eNrz4A12DQ729PeL9%2FV3cfUx8KvOTLFSMnKztDQxsDA0cDI3MzUzdDIzczMyM3K1sLQ0dXMzMXBU0kkusTI0sTAzNzY1NDc3MLDUSUxGE8itsDKojQIAkVcXsA%3D%3D; session=eyJhdXRoIjoiYSJ9.DTd7BQ.umPBQ6ga1aZfzzoskgnkcYs5CQ4; JSESSIONID=oEDI1SmO868ALCuw2N5stCL3pdFtbQRbdxgEeWtd

问题来了，我用隐私模式打开该地址，得到结果如下：

GET / HTTP/1.1
Host: localhost:19999
Connection: keep-alive
Cache-Control: max-age=0
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/64.0.3282.167 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,image/apng,*/*;q=0.8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9,en;q=0.8,sq;q=0.7

请问第一次请求中的cookie信息如何来的，是浏览器的吗