Why do I see "\r\n\r\n" in the HTTP header while launching DoS attack from slowhttptest?

According to the slowloris attack, it sends only part of HTTP header and never sends complete HTTP header by excluding "\r\n\r\n" from header because these four characters are considered as the end of HTTP header. As a result, web server waits for an indefinite time to receive complete header.

However, while launching attack from slowhttptest, I observed these characters in HTTP header using wireshark. Though the attack is working fine, I am confused why this tool is doing so. I am attaching images for normal scenario (during normal scenario) and attack scenario (during attack scenario) as well. Please help me out in this.