Request:"http://example.com"
GET / HTTP/1.1
Host: example.com
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:53.0) Gecko/20100101 Firefox/53.0
Accept: text/html,application/xml;q=0.9,*/*;q=0.8
Accept-Charset: UTF-8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate...